Sight has deterioated -RGP's

[Richrapid]

Hello,

I wear RGP's and have been for about 1 year. They have really improved my vision, but I've recently noticed that the vision in my left eye has deteriorated. I've got an appt. soon at the hospital anyway, but was just wondering what happens when you're vision detoritaes and you wear RGP's.

Can it be improved by amending my contact lens prescription, as you would if your sight detoriated and you wear wearing glasses or do they ahve to start consideing other remedies?

[longhoc]

Hi there Rich

For "normal" contact lens wearers, if you can't see as clearly as you used to, it's probably the case that the lens power isn't "strong" enough so you simply need to change the prescription to make the lens do more work. For Keratoconus, there's the additional complication of the "fit" i.e. how well the lens sits on your irregularly shaped cornea. This affects the performance of the lens and the optometrist might need to make adjustments to the way the lens is curved. You might hear when you go for a fitting things such as “it’s sitting a little flat” or “that’s a bit too steep”. This just means that either the lens has too much of a gap between the underside of it and the front of cornea or that there’s too little gap and the edges of the lens press down on the surface of the eye. Changes in position of the lens change the properties of it and it might end up not doing what it was designed to do. The result to the wearer looks like they need a stronger lens, but in fact the prescription doesn’t need changing, just the way the lens fits. It’s a bit more complicated than that, but that’s the general idea.

My favourite website covering this topic is:

http://www.opt.indiana.edu/lowther/html ... manage.htm

… it’s a good balance of technical info, terminology, fitting issues and solutions – without getting too heavy.

There can be other, less common, reasons such as the onset of scarring where the normally clear eye gets made opaque to a degree – this results in less good vision and can’t be fixed by changing the lens. This is much more likely in more advanced cases of Keratoconus so for yourself it’ll almost certainly be either the lens prescription or the fit that will need to be amended – maybe a bit of both.

I find it helpful to ask the optometrist in the clinic to explain what’s going on, why this- or that- is being done, what it means in English etc. etc. so you get to know a bit more about your condition. With luck, you’ll only need to go once or twice a year for the odd “tweak” though.

Best wishes, come back and ask if there's anything else you need to know. There’s a variety of experts who can chip in with anything more technical if needed plus the rest of us who've been there and done that !

Chris

[Richrapid]

Thanks for the helpful info Chris