Hi! Beginner Qs about Biofinity!

happyeaster · #1 (**permalink**) 07-03-2011, 04:54 AM

hi guys,

Just registered to ask about Biofinity - I normally wear the air optix day and night but unfortunately, like many users the latest ones just suck...

I've heard many users switched to biofinity so I'd like to know -

Do these lenses have a blue tint? The old gen air optix didn't and I would really prefer my eyes not to be surrounded by blue when I wear them

Also - can they be worn up for 29 days? I googled this and some sites list them as 6 days continuous wear, while others (online stores) don't even list them under "extended wear" but instead as daily disposables!

Thanks guys!

Starr · #2 (**permalink**) 07-05-2011, 10:51 AM

Quote:

Originally Posted by happyeaster

hi guys,

Just registered to ask about biofinity - I normally wear the air optix day and night but unfortunately, like many users the latest ones just suck...

I've heard many users switched to biofinity so I'd like to know -

Do these lenses have a blue tint? The old gen air optix didn't and I would really prefer my eyes not to be surrounded by blue when I wear them

Also - can they be worn up for 29 days? I googled this and some sites list them as 6 days continuous wear, while others (online stores) don't even list them under "extended wear" but instead as daily disposables!

Thanks guys!

Biofinity lenses are monthly contact lenses, which means that you can wear them for 30 days and 29 nights. I've never heard of them being daily disposables. That could get very expensive.

Biofinity lenses have what's called a "visibility tint." It's a very, very light blue tint that makes them easier to see if you drop one in the sink or on the floor, but they won't change the color of your eyes.

Wick · #3 (**permalink**) 07-07-2011, 06:18 PM

Quote:

Originally Posted by happyeaster

hi guys,

Just registered to ask about biofinity - I normally wear the air optix day and night but unfortunately, like many users the latest ones just suck...

I've heard many users switched to biofinity so I'd like to know -

Do these lenses have a blue tint? The old gen air optix didn't and I would really prefer my eyes not to be surrounded by blue when I wear them

Also - can they be worn up for 29 days? I googled this and some sites list them as 6 days continuous wear, while others (online stores) don't even list them under "extended wear" but instead as daily disposables!

Thanks guys!

Have you had a problem removing your Biofinity lenses?

dragongirl81 · #4 (**permalink**) 07-08-2011, 11:08 AM

Quote:

Originally Posted by Wick

Have you had a problem removing your Biofinity lenses?

I can't say that I have. How about you?

Wick · #5 (**permalink**) 07-08-2011, 12:12 PM

Quote:

Originally Posted by dragongirl81

I can't say that I have. How about you?

Yes, had a hard time. Luckily I was the doctor's office when I was trying them, got the right one out but he had to remove the left one. I'm hesitant to try these again.

Iseeall · #6 (**permalink**) 07-08-2011, 02:08 PM

Quote:

Originally Posted by Wick

Yes, had a hard time. Luckily I was the doctor's office when I was trying them, got the right one out but he had to remove the left one. I'm hesitant to try these again.

Was that your first time wearing contact lenses, Wick?

Hey, you're not that guy from The Drew Carey Show, are you?

Wick · #7 (**permalink**) 07-08-2011, 02:57 PM

Quote:

Originally Posted by Iseeall

Was that your first time wearing contact lenses, Wick?

Hey, you're not that guy from The Drew Carey Show, are you?

Ha, no not Drew! Acutally I just started about a month ago so I am really new to them, but I had no problems with the Proclear Toric. Removed them very easily. But I keep thinking about how clear the vision was in the Biofinity Toric. I may give them another shot to make sure it's just not something I'd have to get used to but I did see other posts where I've read others having the same problem getting them out.

timetraveler · #8 (**permalink**) 07-08-2011, 03:07 PM

Quote:

Originally Posted by Wick

Ha, no not Drew! Acutally I just started about a month ago so I am really new to them, but I had no problems with the ProClear Toric. Removed them very easily. But I keep thinking about how clear the vision was in the Biofinity Toric. I may give them another shot to make sure it's just not something I'd have to get used to but I did see other posts where I've read others having the same problem getting them out.

It's generally a good idea to keep working with a new brand of contact lenses. So the ProClear lenses just went right in and came right out no problem, huh. I guess you're not used to struggling then. That's okay. Lots of people have trouble with their contact lenses at first, no matter what kind they are. Keep trying and keep in touch with your doctor. He may be able to do something that's even more effective than my pep talk.

Wick · #9 (**permalink**) 07-08-2011, 03:39 PM

Quote:

Originally Posted by timetraveler

It's generally a good idea to keep working with a new brand of contact lenses. So the ProClear lenses just went right in and came right out no problem, huh. I guess you're not used to struggling then. That's okay. Lots of people have trouble with their contact lenses at first, no matter what kind they are. Keep trying and keep in touch with your doctor. He may be able to do something that's even more effective than my pep talk.

Thanks! It's nice to have the support!

timetraveler · #10 (**permalink**) 07-08-2011, 04:12 PM

Quote:

Originally Posted by Wick

Thanks! It's nice to have the support!

You're welcome. That's why Lens 101 is here. If you have any more questions about Biofinity, or even about glasses or sunglasses, just ask Lens 101.

dragongirl81 · #11 (**permalink**) 07-25-2011, 04:18 PM

Quote:

Originally Posted by Wick

Ha, no not Drew!

You're not Mr. Wick are you? If you are . . . welcome to Lens 101. If you're not . . . welcome to Lens 101.

Contact Lens Fitter · #12 (**permalink**) 07-25-2011, 07:58 PM

The Biofinity Toric is only available in one size (8.6). The Proclear is available in two 8.4 and 8.8. The 8.8 proclear does not fit as tightly to the eye as the 8.6, so that would account for the hard time removing it. The 'visi-tint' is very pale and only seen against a white background so you can see it in the case better.contacts pick up dust, dirt and whatever else is in the air and so should be cleaned regularly. It's healthier to wear the same socks and underwear for 29 days at a time than contct lenses.

Wick · #13 (**permalink**) 07-26-2011, 06:21 AM

Quote:

Originally Posted by Contact Lens Fitter

The Biofinity Toric is only available in one size (8.6). The Proclear is available in two 8.4 and 8.8. The 8.8 proclear does not fit as tightly to the eye as the 8.6, so that would account for the hard time removing it. The 'visi-tint' is very pale and only seen against a white background so you can see it in the case better.Contacts pick up dust, dirt and whatever else is in the air and so should be cleaned regularly. It's healthier to wear the same socks and underwear for 29 days at a time than contct lenses.

Thanks for that info on size. It sounds like that could be the reason. I also would imagine for the lens to not rotate as much as a regular toric it has to conform to the eye better.

Deepurple · #14 (**permalink**) 07-26-2011, 09:15 AM

Quote:

Originally Posted by Contact Lens Fitter

The Biofinity Toric is only available in one size (8.6). The Proclear is available in two 8.4 and 8.8. The 8.8 proclear does not fit as tightly to the eye as the 8.6, so that would account for the hard time removing it. The 'visi-tint' is very pale and only seen against a white background so you can see it in the case better. Contacts pick up dust, dirt and whatever else is in the air and so should be cleaned regularly. It's healthier to wear the same socks and underwear for 29 days at a time than contact lenses.

What an interesting post, contact lens Fitter. I like how you described Visitint as "only seen against a white background." That's much simpler than some of the explanations I've offered.
I also like what you said about socks and underwear. There are probably some people out there who don't think twice about wearing their contacts for weeks without cleaning them, but they will recoil in horror from your underwear comparison. Let's hope they do and change their ways--and their contacts.

eyeedoc · #15 (**permalink**) 08-04-2011, 01:55 PM

Quote:

Originally Posted by Contact Lens Fitter

The Biofinity Toric is only available in one size (8.6). The Proclear is available in two 8.4 and 8.8. The 8.8 proclear does not fit as tightly to the eye as the 8.6, so that would account for the hard time removing it. The 'visi-tint' is very pale and only seen against a white background so you can see it in the case better.Contacts pick up dust, dirt and whatever else is in the air and so should be cleaned regularly. It's healthier to wear the same socks and underwear for 29 days at a time than contct lenses.

The Biofinity sphere lenses have a base curve of 8.6 , diameter of 14.0 the biofinity toric lenses have a base curve of 8.7 , diameter 14.2..... The base curve is designed to fit the shape of the front surface of the eye as measure with a keratometer. " k" readings. the avg corneal k reading is ~44.00 ish. Most Contact lenses these days fit a base curve close to an 8.6 because its kind of like a one size fits all base curve.
-Cheers

FantasyEyeland · #16 (**permalink**) 08-04-2011, 02:03 PM

Quote:

Originally Posted by eyeedoc

The Biofinity sphere lenses have a base curve of 8.6 , diameter of 14.0 the biofinity toric lenses have a base curve of 8.7 , diameter 14.2..... The base curve is designed to fit the shape of the front surface of the eye as measure with a keratometer. " k" readings. the avg corneal k reading is ~44.00 ish. Most Contact lenses these days fit a base curve close to an 8.6 because its kind of like a one size fits all base curve.
-Cheers

Awesome. We've got another eye doctor on board! Welcome to Lens 101. Thanks for telling us what the most common base curve is. I've been wondering about that.

One more question, and I hope you can answer it simply. Why is the "k" reading not even close to the base curve number?

eyeedoc · #17 (**permalink**) 08-04-2011, 07:44 PM

Quote:

Originally Posted by FantasyEyeland

Awesome. We've got another eye doctor on board! Welcome to Lens 101. Thanks for telling us what the most common base curve is. I've been wondering about that.

One more question, and I hope you can answer it simply. Why is the "k" reading not even close to the base curve number?

Hi, The K reading is a dioptric value of the power of a persons cornea. The base curve deals in a different value using a radius of half a circle..... depending on the material and what not, and I am trying not to get too technical ... but you take the index of air which is 1 and subtract it by the index of most contact lens materials which is usually 1.3375 and you get .3375 and you divide that number by the radius , which gives you a power. So in other words if you divide a number by a smaller number you get a bigger number..... if you have a steep cornea say 50.00 diopters, you need a smaller base curve to give you that bigger number. if you have a flat cornea say 38.00 diopters, you need a larger base curve to give you that smaller number of 38..... There is a lot of optics / physics of light / = math that goes into contacts,......mostly people have an avg k reading of 44ish, so therefore and avg base curve was made to accomodate most people which is 8.6/8.7 ish....hope this helps.
-cheers

Ordersixtysix · #18 (**permalink**) 08-05-2011, 12:08 PM

Quote:

Originally Posted by eyeedoc

Hi, The K reading is a dioptric value of the power of a persons cornea. The base curve deals in a different value using a radius of half a circle..... depending on the material and what not, and I am trying not to get too technical ... but you take the index of air which is 1 and subtract it by the index of most contact lens materials which is usually 1.3375 and you get .3375 and you divide that number by the radius , which gives you a power. So in other words if you divide a number by a smaller number you get a bigger number..... if you have a steep cornea say 50.00 diopters, you need a smaller base curve to give you that bigger number. if you have a flat cornea say 38.00 diopters, you need a larger base curve to give you that smaller number of 38..... There is a lot of optics / physics of light / = math that goes into contacts,......mostly people have an avg k reading of 44ish, so therefore and avg base curve was made to accomodate most people which is 8.6/8.7 ish....hope this helps.
-cheers

Okay, I read this and got "you take the index of air which is 1 and subtract it by the index of most contact lens materials which is usually 1.3375 and you get .3375 and blah blah blah." Sorry eyeedoc, but math just isn't my thing. Maybe everyone else will understand that and think it's great. I got the last part though, about the average base curve. Thank you for your time.

Contact Lens Fitter · #19 (**permalink**) 08-05-2011, 07:09 PM

The keratometer is designed to measure the cornea in both mm.s and diopters. The number 1.3375 is the refractive index of the cornea, not the lens material. If the average measurement is 44.00ish the the average BC should be 7.67ish. It is far easier to fit CL by trial and error while examining them on the eye than by K readings. You HAVE TO SEE the lens on the eye to determine if it fits or not.

eyeedoc · #20 (**permalink**) 08-05-2011, 07:46 PM

Quote:

Originally Posted by Contact Lens Fitter

The keratometer is designed to measure the cornea in both mm.s and diopters. The number 1.3375 is the refractive index of the cornea, not the lens material. If the average measurement is 44.00ish the the average BC should be 7.67ish. It is far easier to fit CL by trial and error while examining them on the eye than by K readings. You HAVE TO SEE the lens on the eye to determine if it fits or not.

The keratometer indirectly measures the dioptric value of a surface using the radius of curvature of that surface in mm's. And you are correct the 1.3375 is the cornea not the lens material. I thought it would be too confusing to talk about the tear lens and going from air, skipping the material and going straight to the cornea. You are also right that you need to SEE the lens on the eye to determine if it fits, however you should have a good starting point. If the cornea has a flattest K reading of 52.00 well they probably have kerataconus but you dont want to start with a 8.6/8.7 base curve, you wanna start much lower than that like 8.2 . ( although If they really had a 52.00 flattest k reading , they would more than likely have kerataconus and I would fit it with a scleral lens to vault over the cornea).
cheers

Contact Lens Fitter · #21 (**permalink**) 08-06-2011, 10:59 AM

I'm sure I'm not the only person here that's a little confused. I fail to see how the numbers work.
Average K is 44.00D=7.67mm BC---The size that fits almost all people is 8.6/8.7 BC--We should start the fitting process with 8.2 BC. ???

Spicegurl · #22 (**permalink**) 08-08-2011, 11:01 AM

Quote:

Originally Posted by Contact Lens Fitter

I'm sure I'm not the only person here that's a little confused. I fail to see how the numbers work.
Average K is 44.00D=7.67mm BC---The size that fits almost all people is 8.6/8.7 BC--We should start the fitting process with 8.2 BC. ???

How can the "average" and the "size that fits most people" be different? What's "K" again?

Contact Lens Fitter · #23 (**permalink**) 08-08-2011, 01:59 PM

Quote:

Originally Posted by Spicegurl

How can the "average" and the "size that fits most people" be different? What's "K" again?

The 'K' reading is the measurement of the curvature of the cornea. In the example above, 44.00 is the measurement in Diopters (or power) and 7.67 is the measurement in mms. As for 'average' and BC that fits most people, I'm cofused myself as to how those numbers were attained. In thirty years of fitting CLs, I have never seen this confusion of numbers.

Pudgefisk · #24 (**permalink**) 08-08-2011, 02:06 PM

Quote:

Originally Posted by Contact Lens Fitter

The 'K' reading is the measurement of the curvature of the cornea. In the example above, 44.00 is the measurement in Diopters (or power) and 7.67 is the measurement in mms. As for 'average' and BC that fits most people, I'm cofused myself as to how those numbers were attained. In thirty years of fitting CLs, I have never seen this confusion of numbers.

Thanks for explaining that "K" thing. As for those numbers, I'm afraid I can't help you.

HydroRunner · #25 (**permalink**) 08-14-2011, 04:19 AM

Quote:

Originally Posted by Pudgefisk

Thanks for explaining that "K" thing. As for those numbers, I'm afraid I can't help you.

I'll explain it: eyeedoc wrote: "you get .3375 and you divide that number by the radius, which gives you a power". The radius in meters, of course. Examples:

.3375 / 0.0086 = 39.25 i.e. radius of 8.6mm corresponds to k reading of 39.25

.3375 / 0.0076 = 44.4 i.e. radius of 7.6mm corresponds to k reading of 44.4

So you change the millimeters to meters before you compute anything!

Another confusing thing: it was stated that most people have a K reading of 44, which means a curvature radius of 7.6 mm, but most soft contatcts have a back curvature radius around 8.6 mm. Clearly different. But they do not have to be the same. In fact it is to be expected that the back of the lens should be less curved than the front of the eye to prevent the lens from getting stuck. (And the larger value of 8.6 for the lens BC does indeed mean that it is less curved then the cornea with radius 7.6mm!)

This summarizes (hopefully a bit clearer) what was stated by eyeedoc and others in this thread. Whether their statements are true is beyound my judgement, but we can at least understand what they claim.

Contact Lens Fitter · #26 (**permalink**) 08-14-2011, 07:48 PM

It is FAR easier to fit soft CLs by trial and error than by 'K' readings. The keratometer measures aprox. 3.5mms. of a 12.5mm. (aprox) cornea. Considering the cornea is NOT one smooth curve, we have many irregularities. The cornea's shape is more like a 'nipple' than a smooth curve.When we measure the corneal cap, we ASSUME the rest of the cornea will follow an accepted pattern. If it doesn't, then it's anybody's guess as to what will fit. The ONLY WAY to determine if a lens fits is to observe it on the eye with a bio-microscope.

OzzieG · #27 (**permalink**) 08-15-2011, 12:25 PM

Quote:

Originally Posted by Contact Lens Fitter

It is FAR easier to fit soft CLs by trial and error than by 'K' readings. The keratometer measures aprox. 3.5mms. of a 12.5mm. (aprox) cornea. Considering the cornea is NOT one smooth curve, we have many irregularities. The cornea's shape is more like a 'nipple' than a smooth curve.When we measure the corneal cap, we ASSUME the rest of the cornea will follow an accepted pattern. If it doesn't, then it's anybody's guess as to what will fit. The ONLY WAY to determine if a lens fits is to observe it on the eye with a bio-microscope.

It's a good thing I talked myself out of posting a picture illustrating that cornea/nipple thing.

Thanks for explaining about the complex curvature of the cornea, Contact Lens Fitter.

Iseeall · #28 (**permalink**) 10-19-2011, 02:24 PM

Quote:

Originally Posted by Contact Lens Fitter

It is FAR easier to fit soft CLs by trial and error than by 'K' readings. The keratometer measures aprox. 3.5mms. of a 12.5mm. (aprox) cornea. Considering the cornea is NOT one smooth curve, we have many irregularities. The cornea's shape is more like a 'nipple' than a smooth curve.When we measure the corneal cap, we ASSUME the rest of the cornea will follow an accepted pattern. If it doesn't, then it's anybody's guess as to what will fit. The ONLY WAY to determine if a lens fits is to observe it on the eye with a bio-microscope.

Thanks for giving us the benefit of your experience with fitting contact lenses.

Hey, do you think you can post a picture of one of those bio-microscopes?