Acuvue Oasys for Astigmatism For Those With Narrow Eyes

Spookytooth · #1 (**permalink**) 10-20-2008, 12:15 PM

How is it to wear Acuvue Oasys for Astigmatism contact lenses for those people who have narrow eyes? Does that help by keeping them from rotating?

jacklsw86 · #2 (**permalink**) 01-31-2010, 11:34 AM

yeah. i've been wondering about this too. i'm an asian chinese and i have quite a small pair of eyes. i have a feeling that i can see clearer when i open my eyes bigger. it would be quite disappointing if the Acuvue oasys's lens stability only suits the people with bigger eyes.

Tiger · #3 (**permalink**) 02-01-2010, 12:46 PM

Quote:

Originally Posted by jacklsw86

yeah. i've been wondering about this too. i'm an asian chinese and i have quite a small pair of eyes. i have a feeling that i can see clearer when i open my eyes bigger. it would be quite disappointing if the acuvue oasys's lens stability only suits the people with bigger eyes.

Hi jacklsw86,

Please allow me to welcome you to Lens 101. Do you currently wear Acuvue Oasys for Astigmatism contact lenses?
I've seen a few questions on here about Asians and contacts, and I've never read about their having problems with contact lenses.
I find it interesting that you can see more clearly when you open our eyes up more while other people have to squint.
Please let us know here at Lens 101 if you have any more questions, and we'll try to help.

jacklsw86 · #4 (**permalink**) 02-04-2010, 07:49 AM

i think i figure out the problem for my case. i wear the contact lens early in the morning after waking up, brushing my teeth and washing my face. after wearing them, i proceed to applying hair wax. at this time, i keep looking up for about 5 mins. i wonder if by looking up for a while just after putting on the lens would make the lens become incorrectly adjusted in the eyes? thanks for helping out

mayibfrank · #5 (**permalink**) 02-04-2010, 09:39 AM

Quote:

Originally Posted by jacklsw86

i think i figure out the problem for my case. i wear the contact lens early in the morning after waking up, brushing my teeth and washing my face. after wearing them, i proceed to applying hair wax. at this time, i keep looking up for about 5 mins. i wonder if by looking up for a while just after putting on the lens would make the lens become incorrectly adjusted in the eyes? thanks for helping out

Hi jacklsw86,

Do you mean you're looking up as your applying the hair wax? I don't see how that could cause problems with vision, but I suppose it's possible. I'm not an expert in contact lenses, although I've been learning a lot from Lens 101. I guess the obvious thing to do would be to go through your regular routine, just skip the styling stuff and see if it makes a difference.

Spookytooth · #6 (**permalink**) 02-23-2010, 05:49 PM

Thank you for your responses jacklsw86 and Tiger. This is a good discussion and I hope to hear from you again soon.

mayibfrank · #7 (**permalink**) 03-05-2010, 12:08 PM

Quote:

Originally Posted by jacklsw86

i think i figure out the problem for my case. i wear the contact lens early in the morning after waking up, brushing my teeth and washing my face. after wearing them, i proceed to applying hair wax. at this time, i keep looking up for about 5 mins. i wonder if by looking up for a while just after putting on the lens would make the lens become incorrectly adjusted in the eyes? thanks for helping out

Hi jacklsw86. How are things? Have you figured out what your issue was with your contacts?

jacklsw86 · #8 (**permalink**) 03-05-2010, 12:36 PM

yeah i don't have issues anymore with this contact lens. perhaps it takes more than 1 month for myself to get adjusted to the new lens.

Logopolis · #9 (**permalink**) 03-05-2010, 02:05 PM

Quote:

Originally Posted by jacklsw86

yeah i don't have issues anymore with this contact lens. perhaps it takes more than 1 month for myself to get adjusted to the new lens.

Hey, that's great Jack. Great to know the contacts worked out for you.

Tiger · #10 (**permalink**) 03-09-2010, 04:34 PM

Quote:

Originally Posted by mayibfrank

Hi jacklsw86,

Do you mean you're looking up as your applying the hair wax? I don't see how that could cause problems with vision, but I suppose it's possible. I'm not an expert in contact lenses, although I've been learning a lot from Lens 101. I guess the obvious thing to do would be to go through your regular routine, just skip the styling stuff and see if it makes a difference.

Perhaps as you're looking upward at your head or your hands busily working gravity causes your contacts to slide down out of place. What do you think? Is that plausible?

Doctor G · #11 (**permalink**) 03-09-2010, 07:55 PM

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down. This is sometimes called "the watermelonseed principle". The smaller the apeture opening between the lids, the BETTER the lenses will orient, at least in theory. The Oasys for Astigmatism uses a modified version of the usual thickness gradient which thins the very bottom, to improve comfort, leaving the thickest areas to the sides of the bottom half of the lens. In actual use, any unusual squeezing of the eyelids can make the lens rotate a little, and blur the vision.

captainneo · #12 (**permalink**) 03-10-2010, 09:40 AM

Quote:

Originally Posted by Doctor G

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down. This is sometimes called "the watermelon seed principle". The smaller the aperture opening between the lids, the BETTER the lenses will orient, at least in theory. The Oasys for Astigmatism uses a modified version of the usual thickness gradient which thins the very bottom, to improve comfort, leaving the thickest areas to the sides of the bottom half of the lens. In actual use, any unusual squeezing of the eyelids can make the lens rotate a little, and blur the vision.

Greetings, Doctor G. Welcome to Lens 101.

Thank you for that interesting explanation about how toric contacts work. I thought it was gravity that held them in the proper orientation, but now I know better. Stick around and see how else you can help this forum.

Logopolis · #13 (**permalink**) 03-10-2010, 05:22 PM

Quote:

Originally Posted by Doctor G

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down. This is sometimes called "the watermelonseed principle". The smaller the apeture opening between the lids, the BETTER the lenses will orient, at least in theory. The Oasys for Astigmatism uses a modified version of the usual thickness gradient which thins the very bottom, to improve comfort, leaving the thickest areas to the sides of the bottom half of the lens. In actual use, any unusual squeezing of the eyelids can make the lens rotate a little, and blur the vision.

Very cool, Doctor G. I guess I always thought it was gravity, too.

Tell me a little more about this "watermelon seed principle." Does that refer to how the seeds squirt out of your fingers when you squeeze them?

Doctor G · #14 (**permalink**) 03-10-2010, 06:43 PM

Quote:

Originally Posted by Logopolis

Very cool, Doctor G. I guess I always thought it was gravity, too.

Tell me a little more about this "watermelon seed principle." Does that refer to how the seeds squirt out of your fingers when you squeeze them?

Yes.
Recall that the seed is fatter at the rounded end, and gets slimmer toward the point. Since it is well lubricated, moderate finger pressure causes the thicker portion to be moved away from the point of contact. This term as applied to toric contacts was coined by an Aussie eye doc named A J (Tony) Hanks. I first heard it from him in San Diego at a lecture sponsored by Ciba, and he later published it in a now defunct professional journal called Contact Lens Forum, in Sept of 1983.

In the case of the toric contact, realize that the lens has two differnt optical powers in it, at axes separated by 90 degrees. The part of the lens which needs to be at the top, to deliver the correct positions on the eye for the two powers, is always the thinnest part, in all designs. Most brands simply get thicker as they progress toward the part which needs to be down. One design (the old Ciba Torisoft) actually had a thin top and a thin bottom, and was fat in the center. That as called a "twin thin zone", and had so-so success. The modern Acuvues, such as Oasys for Astigmatism, use a modifed design with thick zones to the sides near the bottom, as I previously mentioned.

Another idea a few lenses tried to enhance stability was to simply chop off some of the thick edge of the lens at the bottom, and let the straight line edge sit on the eyelid. This is called truncation, and doesnt work very well.

Aaroncablemom · #15 (**permalink**) 03-11-2010, 10:34 AM

Quote:

Originally Posted by Doctor G

Yes.
Recall that the seed is fatter at the rounded end, and gets slimmer toward the point. Since it is well lubricated, moderate finger pressure causes the thicker portion to be moved away from the point of contact. This term as applied to toric contacts was coined by an Aussie eye doc named A J (Tony) Hanks. I first heard it from him in San Diego at a lecture sponsored by Ciba, and he later published it in a now defunct professional journal called Contact Lens Forum, in Sept of 1983.

In the case of the toric contact, realize that the lens has two differnt optical powers in it, at axes separated by 90 degrees. The part of the lens which needs to be at the top, to deliver the correct positions on the eye for the two powers, is always the thinnest part, in all designs. Most brands simply get thicker as they progress toward the part which needs to be down. One design (the old Ciba Torisoft) actually had a thin top and a thin bottom, and was fat in the center. That as called a "twin thin zone", and had so-so success. The modern Acuvues, such as Oasys for Astigmatism, use a modifed design with thick zones to the sides near the bottom, as I previously mentioned.

Another idea a few lenses tried to enhance stability was to simply chop off some of the thick edge of the lens at the bottom, and let the straight line edge sit on the eyelid. This is called truncation, and doesnt work very well.

Awsome. Thanks for the lesson on toric lenses, Doctor G. It was very interesting. Are you a "real" doctor or do you just play one in forums? Stick around. Your knowledge will be very useful around here. We need more people answering questions.

Doctor G · #16 (**permalink**) 03-11-2010, 02:42 PM

I am an Optometrist, in practice for 30 years.

Spookytooth · #17 (**permalink**) 03-11-2010, 03:10 PM

Quote:

Originally Posted by Doctor G

I am an Optometrist, in practice for 30 years.

You are? Fantastic! Welcome to Lens 101. We've already got a few people with medical credentials and their contributions are invaluable. I look forward to your future posts, Doctor G. Make sure to look around in all the different categories here.

Doctor G · #18 (**permalink**) 03-12-2010, 03:58 AM

Thanks.
Its not my intention to try to horn in and act all uppity, tho.
I just enjoy seeing what experiences patients from all over have had with the various products.

I realize this is really a users forum, but Im happy to weigh in when it seems appropriate.

eye2eye · #19 (**permalink**) 03-12-2010, 09:51 AM

Quote:

Originally Posted by Doctor G

Thanks.
Its not my intention to try to horn in and act all uppity, tho.
I just enjoy seeing what experiences patients from all over have had with the various products.

I realize this is really a users forum, but Im happy to weigh in when it seems appropriate.

Hi Doctor G. Welcome to Lens 101.

I don't see how you can "horn in." To me that means to interrupt a conversation. In a forum such as this, these are not private conversations, so anyone is welcome to comment, especially if they have professional experience and credentials such as yourself. Anyone can give their opinion, but if you can answer from your experience or education, that's great.

However, we don't tolerate "uppity" very well.

jacklsw86 · #20 (**permalink**) 03-14-2010, 02:16 AM

Quote:

Originally Posted by Doctor G

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down. This is sometimes called "the watermelonseed principle". The smaller the apeture opening between the lids, the BETTER the lenses will orient, at least in theory. The Oasys for Astigmatism uses a modified version of the usual thickness gradient which thins the very bottom, to improve comfort, leaving the thickest areas to the sides of the bottom half of the lens. In actual use, any unusual squeezing of the eyelids can make the lens rotate a little, and blur the vision.

hey dr G,
so are you saying that people with narrow eyes would fare better wearing toric contact lens?

mamcita · #21 (**permalink**) 03-15-2010, 09:27 AM

Quote:

Originally Posted by Doctor G

Thanks.
Its not my intention to try to horn in and act all uppity, tho.
I just enjoy seeing what experiences patients from all over have had with the various products.

I realize this is really a users forum, but I'm happy to weigh in when it seems appropriate.

Thanks for your help, Doctor G. I hope you'll keep coming back to Lens 101 to share your expertise.

Aaroncablemom · #22 (**permalink**) 04-20-2010, 04:24 PM

Quote:

Originally Posted by Doctor G

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down.

Being the nerd that I am, when you mention gravity, I have to ask if toric lenses would still work in microgravity, seeing that it's eyelid pressure rather than gravity that keeps the torics in place?

Doctor G · #23 (**permalink**) 04-21-2010, 06:44 PM

Although there might be a very small boost from gravity in the orientation of toric lenses, it is pretty much a lid presssure effect, so I would expect them to do fine in reduced or absent gravity. We can observe that even reversed gravity (hanging up-side down) doesnt make the lenses flip upside down on the eye.

Garfield21 · #24 (**permalink**) 04-22-2010, 12:04 PM

Quote:

Originally Posted by Doctor G

Although there might be a very small boost from gravity in the orientation of toric lenses, it is pretty much a lid presssure effect, so I would expect them to do fine in reduced or absent gravity. We can observe that even reversed gravity (hanging up-side down) doesn't make the lenses flip upside down on the eye.

Excellent observation, Doctor G. Thank you for joining us here on Lens 101, where we can hang out together.

Knotlob · #25 (**permalink**) 04-22-2010, 12:25 PM

Quote:

Originally Posted by Doctor G

Although there might be a very small boost from gravity in the orientation of toric lenses, it is pretty much a lid presssure effect, so I would expect them to do fine in reduced or absent gravity. We can observe that even reversed gravity (hanging up-side down) doesnt make the lenses flip upside down on the eye.

Very interesting to have a better explanation of the more technical issues of toric lens stability Doctor G. I've read about the truncation idea also, but didn't know it didn't work so well in practice.

Funny that most of the lens manufacturer's literature seems to stress gravity as the orienting force in toric lenses. Presumably just a case of 'dumbing down' for the layman

I guess toric lens development will continue to improve stability.

One final comment. In bright light/sunshine/snow when the eye lids are almost closed, the toric lenses should work pretty well due to this 'water melon seed' effect?

knotlob

Aaroncablemom · #26 (**permalink**) 04-30-2010, 04:52 PM

Quote:

Originally Posted by Knotlob

Very interesting to have a better explanation of the more technical issues of toric lens stability Doctor G. I've read about the truncation idea also, but didn't know it didn't work so well in practice.

Funny that most of the lens manufacturer's literature seems to stress gravity as the orienting force in toric lenses. Presumably just a case of 'dumbing down' for the layman

knotlob

I know what you mean about the "dumbing down" of the explanation for toric lenses. What's so hard about explaining that toric lenses have one section of the contact lens that's a little thicker than the rest, so the eyelids tend to push that part to the bottom? See? Easy. Throw in an illustration, and a caveman can understand it.

Doctor G · #27 (**permalink**) 04-30-2010, 06:06 PM

Quote:

Originally Posted by Knotlob

Very interesting to have a better explanation of the more technical issues of toric lens stability Doctor G. I've read about the truncation idea also, but didn't know it didn't work so well in practice.

Funny that most of the lens manufacturer's literature seems to stress gravity as the orienting force in toric lenses. Presumably just a case of 'dumbing down' for the layman

I guess toric lens development will continue to improve stability.

One final comment. In bright light/sunshine/snow when the eye lids are almost closed, the toric lenses should work pretty well due to this 'water melon seed' effect?

knotlob

Well, maybe. Covering more of the lens with the lid should increase the "watermelonseed" forces, but it may also tend to put more drag on the lens, and actually impede the free rotation on the eye which it needs to orient exactly. Ive honestly never observed a toric on an eye which was squinting significantly, and never have seen it discussed in any reference.

Knotlob · #28 (**permalink**) 04-30-2010, 06:12 PM

Quote:

Originally Posted by Doctor G

Well, maybe. Covering more of the lens with the lid should increase the "watermelonseed" forces, but it may also tend to put more drag on the lens, and actually impede the free rotation on the eye which it needs to orient exactly. Ive honestly never observed a toric on an eye which was squinting significantly, and never have seen it discussed in any reference.

OK, thanks Dr G. I noticed that when I wear RGP lenses (as opposed to a silicone hydrogel soft lens) I have more sensitivity to sunlight and if I didn't wear sun glasses, my eyes may be squinting. (I don't wear a toric lens yet, so the question was out of interest rather than of necessity).

knotlob

Doctor G · #29 (**permalink**) 04-30-2010, 06:19 PM

Quote:

Originally Posted by Aaroncablemom

I know what you mean about the "dumbing down" of the explanation for toric lenses. What's so hard about explaining that toric lenses have one section of the contact lens that's a little thicker than the rest, so the eyelids tend to push that part to the bottom? See? Easy. Throw in an illustration, and a caveman can understand it.

I do a lot of explaining in my practice, and I find that many patients have been given explanations in the past which were not only attempts to be very simple, but are actually factually wrong.

Many eye docs will tell patients that having astigmatism means that the eye is "shaped like a football". I just cringe when I hear that. I picture the patient imagining their cornea with a point at the front. Even if they get it, that the doc meant like the SIDE of a football, its still actually wrong. An astigmatic (toric) cornea is shaped like a section of the side of a do-nut (a torus, in geometry). There are two more or less proper round curves, at a right angle to each other, one more curved than the other. The discussion of torics as being "weighted" is similarly unnecessarily wrong.

Knotlob · #30 (**permalink**) 05-01-2010, 04:05 AM

Quote:

Originally Posted by Doctor G

I do a lot of explaining in my practice, and I find that many patients have been given explanations in the past which were not only attempts to be very simple, but are actually factually wrong.

Many eye docs will tell patients that having astigmatism means that the eye is "shaped like a football". I just cringe when I hear that. I picture the patient imagining their cornea with a point at the front. Even if they get it, that the doc meant like the SIDE of a football, its still actually wrong. An astigmatic (toric) cornea is shaped like a section of the side of a do-nut (a torus, in geometry). There are two more or less proper round curves, at a right angle to each other, one more curved than the other. The discussion of torics as being "weighted" is similarly unnecessarily wrong.

Hello Dr G, Thanks for that explanation. I'm not sure I fully understand that bit about two half toroids, but there was a reference to something like than in an Eye Tec On-Line Tutorial on astigmatism. I must try and read the entire course!

Thanks again

knotlob

mayibfrank · #31 (**permalink**) 05-06-2010, 04:55 PM

Quote:

Originally Posted by Doctor G

I do a lot of explaining in my practice, and I find that many patients have been given explanations in the past which were not only attempts to be very simple, but are actually factually wrong.

Many eye docs will tell patients that having astigmatism means that the eye is "shaped like a football". I just cringe when I hear that. I picture the patient imagining their cornea with a point at the front. Even if they get it, that the doc meant like the SIDE of a football, its still actually wrong. An astigmatic (toric) cornea is shaped like a section of the side of a do-nut (a torus, in geometry). There are two more or less proper round curves, at a right angle to each other, one more curved than the other. The discussion of torics as being "weighted" is similarly unnecessarily wrong.

Hello Doctor G.

I'm not crazy about that "shaped like a football" thing either, because "a football" to someone in Dallas is different from a "football" to a person in London.

Now, tell me about that "weighted toric lenses thing." You mean toric lenses are not weighted? Isn't the part of the lens that's supposed to be on the bottom of the cornea thicker than the rest, like in this exaggerated cross section?

Knotlob · #32 (**permalink**) 05-06-2010, 05:43 PM

Quote:

Originally Posted by mayibfrank

Hello Doctor G.

I'm not crazy about that "shaped like a football" thing either, because "a football" to someone in Dallas is different from a "football" to a person in London.

Now, tell me about that "weighted toric lenses thing." You mean toric lenses are not weighted? Isn't the part of the lens that's supposed to be on the bottom of the cornea thicker than the rest, like in this exaggerated cross section?

I think Doctor G said this was a myth. It's more to do with thickness/profile of the lens in a way resembling the water melon seed being squeezed.

On the two half toroids. Is one half toroid representing the spherical correction component, while the second half toroid represents the astigmatism correction component? Or are both toroid halves part of the astigmatism correction?

My other question if you can answer it, astigmatism correction is described as a cylinder with a negative value. There is never a positive value?

knotlob

Doctor G · #33 (**permalink**) 05-07-2010, 07:11 PM

Quote:

Originally Posted by mayibfrank

Hello Doctor G.

I'm not crazy about that "shaped like a football" thing either, because "a football" to someone in Dallas is different from a "football" to a person in London.

Now, tell me about that "weighted toric lenses thing." You mean toric lenses are not weighted? Isn't the part of the lens that's supposed to be on the bottom of the cornea thicker than the rest, like in this exaggerated cross section?

NO, the stability is NOT from weight in the lens, but YES, they are thicker at the bottom, as you show.. See the explanation in my posts of 3-9-10 amd 3-10-10 regarding the "watermelonseed principle". Its eyelid pressure, not gravity, which orients a toric contact lens.

You are quite right, that a European or South American idea of a "football" would of course, be a SPHERE.

Doctor G · #34 (**permalink**) 05-07-2010, 08:28 PM

Quote:

Originally Posted by Knotlob

I think Doctor G said this was a myth. It's more to do with thickness/profile of the lens in a way resembling the water melon seed being squeezed.

On the two half toroids. Is one half toroid representing the spherical correction component, while the second half toroid represents the astigmatism correction component? Or are both toroid halves part of the astigmatism correction?

My other question if you can answer it, astigmatism correction is described as a cylinder with a negative value. There is never a positive value?

knotlob

Dont think of "half toroids". A toric cornea is shaped like a piece of the side of a do-nut, with one steeper curve and one flatter one. Both curves, considered together, make it "toric". If there arent two different curves, it isnt toric, its just spherical.

An Rx for astigmatism has two different powers in it, at right angles, given in Diopters. It is corrected, at least in part, with a cylindrical lens, which has active optical power only in one direction.

If the eye is also too long or too short, we also use the needed sphereical power, in plus or minus.

SO we can write either format for any astigmatic lens.

in MINUS CYL FORMAT,we write the power which is the more plus, less minus power stated as the SPHERE, and then specify a minus value as the CYL which is the difference between the two powers, going in a minus direction.
the "Axis" is the location of the inactive direction of the cyl.

In PLUS CYL FORMAT, we use the more minus, least plus power as the sphere, and write a plus value for cyl, which is the difference between the two powers needed. The axis will be 90 out of synch with the minus format's axis.

It is of course easy to transpose an Rx from one format to the other.

Building63 · #35 (**permalink**) 05-10-2010, 10:37 AM

Quote:

Originally Posted by Doctor G

NO, the stability is NOT from weight in the lens, but YES, they are thicker at the bottom, as you show.. See the explanation in my posts of 3-9-10 amd 3-10-10 regarding the "watermelonseed principle". Its eyelid pressure, not gravity, which orients a toric contact lens.

You are quite right, that a European or South American idea of a "football" would of course, be a SPHERE.

Thanks for clearing that up, Doctor G. That's why lens 101 is here, to help people to understand the basics of contact lens wear, and to clear up misconception. You and Knbotlob can discuss some of the more complicated stuff too, of course.

Delta88 · #36 (**permalink**) 05-10-2010, 10:46 AM

Quote:

Originally Posted by Doctor G

The way toric (astigmatism) contacts work is by using a thickness gradient. they are thin at the top, and thick at the bottom, to prevent rotation. Altho it superficially seems like a gravity effect, it is actually upper eyelid pressure against the eye which pushes the thicker part down. This is sometimes called "the watermelon seed principle". The smaller the apeture opening between the lids, the BETTER the lenses will orient, at least in theory. The Oasys for Astigmatism uses a modified version of the usual thickness gradient which thins the very bottom, to improve comfort, leaving the thickest areas to the sides of the bottom half of the lens. In actual use, any unusual squeezing of the eyelids can make the lens rotate a little, and blur the vision.

The question above about contact lenses sliding out of place when looking up, is not just about toric lenses, necessarily. It's in the Acuvue Oasys for Astigmatism section, but the answer about toric lenses turning in this case was in the context of someone asking "I wonder if by looking up for a while just after putting on the lens would make the lens become incorrectly adjusted in the eyes?"

captainneo · #37 (**permalink**) 05-27-2010, 03:51 PM

Quote:

Originally Posted by Doctor G

Yes.
Recall that the seed is fatter at the rounded end, and gets slimmer toward the point. Since it is well lubricated, moderate finger pressure causes the thicker portion to be moved away from the point of contact. This term as applied to toric contacts was coined by an Aussie eye doc named A J (Tony) Hanks. I first heard it from him in San Diego at a lecture sponsored by Ciba, and he later published it in a now defunct professional journal called Contact Lens Forum, in Sept of 1983.

So you're telling me that there was a professional journal that contained the phrase "watermelon principle"?

Doctor G · #38 (**permalink**) 05-27-2010, 05:00 PM

Quote:

Originally Posted by captainneo

So you're telling me that there was a professional journal that contained the phrase "watermelon principle"?

Sure. As I said above, the term was coined by an Aussie eye doc named Tony Hanks, in the early eighties. (BTW he had a really cool ZZ Top-style beard, back then)...I saw him lecture in San Diego, about 1983 or so, and he used the term very confidently, assuming we all knew it...

Here is an article from 2006, by a Vistakon (Accuvue) consultant, also using the term as if it is common knowlege among eye docs:

http://www.optometry.co.uk/articles/docs/ba8f05afbd59cf3e4da6395e19ba7f07_Resnick_5506.pdf

OzzieG · #39 (**permalink**) 05-28-2010, 11:59 AM

Quote:

Originally Posted by Doctor G

Sure. As I said above, the term was coined by an Aussie eye doc named Tony Hanks, in the early eighties. (BTW he had a really cool ZZ Top-style beard, back then)...I saw him lecture in San Diego, about 1983 or so, and he used the term very confidently, assuming we all knew it...

Here is an article from 2006, by a Vistakon (Accuvue) consultant, also using the term as if it is common knowledge among eye docs:

http://www.optometry.co.uk/articles/docs/ba8f05afbd59cf3e4da6395e19ba7f07_Resnick_5506.pdf

I tried to find a picture of Dr. Hanks and his ZZ Top beard, but all Google came up with was a bunch of pictures of skateboarder/slacker Tony Hawks.

Seriously, who would pay someone to ride a skateboard all day?

Thanks for that watermelon seed thing, too.

Doctor G · #40 (**permalink**) 05-28-2010, 02:16 PM

Quote:

Originally Posted by OzzieG

I tried to find a picture of Dr. Hanks and his ZZ Top beard, but all Google came up with was a bunch of pictures of skateboarder/slacker Tony Hawks.

Seriously, who would pay someone to ride a skateboard all day?

Thanks for that watermelon seed thing, too.

This article also references the WSP,
http://www.clspectrum.com/article.aspx?article=102540

...and this is the citation to the original article. Sorry I couldnt find a link to the text...the magazine Contact Lens Forum is no longer published, so doesnt have a website. Any good Optometry library, (like the one at UC Berkeley) would have the magazine in their collection.

Hanks AJ. The watermelon seed principle. Contact Lens Forum 1983;9:31-5.

Ill keep trying to find a picture of Dr Hanks.

Meanwhile, you shouldnt dis Tony Hawk. I used to watch Tony Hawk (no "s") skate when he was a kid, at the Del Mar Skate Ranch. His mom used to drive him over to the coast from Escondido, and sit patiently and watch him as he ripped in the infamous "keyhole" bowl. My son was the same age, and also skated there. Tony was about 12, at the time, and really skinny, hence the nickname "bones" and the Hawk skull logo. He was an amazing talent, even then, and has grown up to be a very handsome and well mannered guy.

Guinness · #41 (**permalink**) 05-28-2010, 03:31 PM

Quote:

Originally Posted by Doctor G

This article also references the WSP,
http://www.clspectrum.com/article.aspx?article=102540

...and this is the citation to the original article. Sorry I couldnt find a link to the text...the magazine Contact Lens Forum is no longer published, so doesnt have a website. Any good Optometry library, (like the one at UC Berkeley) would have the magazine in their collection.

Hanks AJ. The watermelon seed principle. Contact Lens Forum 1983;9:31-5.

Ill keep trying to find a picture of Dr Hanks.

Meanwhile, you shouldn't dis Tony Hawk. I used to watch Tony Hawk (no "s") skate when he was a kid, at the Del Mar Skate Ranch. His mom used to drive him over to the coast from Escondido, and sit patiently and watch him as he ripped in the infamous "keyhole" bowl. My son was the same age, and also skated there. Tony was about 12, at the time, and really skinny, hence the nickname "bones" and the Hawk skull logo. He was an amazing talent, even then, and has grown up to be a very handsome and well mannered guy.

Hawk. Tony Hawk. Got it. I think OzzieG searched "Tony Hanks" and the only pictures that came close were pictures in which the skater's name was misspelled.

Thanks for posting your personal experience with Mr. Hawk. Was he well-mannered back then? I don't care so much about the "handsome" part.

Back to the topic. Do you suppose Tony Hawk knows anything about Acuvue Oasys for Astigmatism contact lenses or watermelon seeds?

Guinness · #42 (**permalink**) 05-28-2010, 03:58 PM

Quote:

Originally Posted by Delta88

The question above about contact lenses sliding out of place when looking up, is not just about toric lenses, necessarily. It's in the Acuvue Oasys for Astigmatism section, but the answer about toric lenses turning in this case was in the context of someone asking "I wonder if by looking up for a while just after putting on the lens would make the lens become incorrectly adjusted in the eyes?"

I don't know about the contact lens thing, but standing there looking up into the sky will probably get passers by to try and see what you're looking at. Try it sometimes. It's fun.

Garfield21 · #43 (**permalink**) 07-08-2010, 12:18 PM

Quote:

Originally Posted by Aaroncablemom

Being the nerd that I am, when you mention gravity, I have to ask if toric lenses would still work in microgravity, seeing that it's eyelid pressure rather than gravity that keeps the torics in place?

Look ma! No gravity!

Building63 · #44 (**permalink**) 07-08-2010, 04:26 PM

Quote:

Originally Posted by Aaroncablemom

I know what you mean about the "dumbing down" of the explanation for toric lenses. What's so hard about explaining that toric lenses have one section of the contact lens that's a little thicker than the rest, so the eyelids tend to push that part to the bottom? See? Easy. Throw in an illustration, and a caveman can understand it.

Look ma! Cavemen! In a restaurant!

captainneo · #45 (**permalink**) 07-13-2010, 03:42 PM

Quote:

Originally Posted by Guinness

Back to the topic. Do you suppose Tony Hawk knows anything about Acuvue Oasys for Astigmatism contact lenses or watermelon seeds?

I don't think he needs any vision correction. I tried searching for information on line but I didn't find anything useful. So I'm guessing that Mr. Hawk does not need any corrective lenses.

Spookytooth · #46 (**permalink**) 08-18-2010, 04:50 PM

Quote:

Originally Posted by Doctor G

Thanks.
Its not my intention to try to horn in and act all uppity, tho.
I just enjoy seeing what experiences patients from all over have had with the various products.

I realize this is really a users forum, but Im happy to weigh in when it seems appropriate.

We're glad to have you Doctor G. I see you've already gotten your toes wet. Are you ready to jump in with both feet?