 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Medical Forum / General / Vision / February 2006RGP sweet spot
Hi All, I have been wearing rigid gas permeable lenses for 17 hours a day for 4 and a half years.They are not perfect like normal vision but generaly better than glasses. There is something of a sweet spot where vision is sharpest in the center of the lens.When I move the eye the lens does catch up as it slips across the eye like it is supposed to do and it is sharp again. I guess this is the nature of the beast and it takes getting used to. My presription from memory but not accurate but close is: right eye about -6.75 and left eye about -5.75 and very little astigmatism (maybe .25 ). My optometrist said that I have a very good fit after checking with flourescin strip and ultraviolet light. Do some lens matereals have a larger sweet spot than others? Dennis San Diego CA Wrong address in the original message. This is correct > Hi All, > I have been wearing rigid gas permeable lenses for 17 hours a day for [quoted text clipped - 13 lines] > > San Diego CA No. It is the size of the centrally located optical zone and how stable it's location over the pupil that determines the "sweet spot". Your posts indicates you've experienced that. If this is a new experience for you after 4 years of not, ask your doctor to try to fix it. Sometimes changing the fit by increasing the optic zone and lens diameter helps to keep vision more consistently crisp. A hybrid RGP-center soft lens aims to do just that, too. LB, O.D. I'm not able to tell from your post if your lenses seem to be getting worse over time, or if these are the same pair for 4 years. The old-fashioned hard PMMA lenses were like rock, and they almost never warped or lost their shape. Newer gas perms have silicone and florine in them, and they breath much better...but they warp and flatten over time. A lens that has flattened in its periphery makes a "tear layer" under the edge, which can look a lot like you are describing...clear on center and wavy on the periphery. Thanks for the 2 replies. . I change to a new lens every 8 or 9 weeks. The sweet spot is something I've always noticed. Recently a lens in my right eye was particularly bad as sweet spot is concerned. I changed to a new pair today (after 7 weeks)and a big improvement. That last lens (right) must have been warped (or flat) from the getgo. I probably should have changed it right away.With 4 and a half years of experience with RGP I can tell if something is wrong. But generaly after going through lots of lenses I can always tell there is a sweet spot. I mentioned this to the doc a couple years ago and he agreed that there is an optical center where acuity is the best but he never pursued the matter (unless he did some fine tuning without me knowing) ---if so thats OK. So this sweet spot can be modified slightly by adjusting diameter? Interesting ----I'll ask the Doc about it. I'll leave that decision up to him though.He's the expert. Thats interesting about the new lens matereal thats part rgp and part soft lens. Those guys in the research departments must be always trying to improve things. Thats good. I'm using Paragon HDS . Before that for the first year it was flouroperm 60. I must be answering both responses at the same time. Sorry for any confusion. Dennis San Diego CA
|
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.