On 1/31/2011 4:40 AM, Dave Howorth wrote:
It's quite important to have a specific pair of specs for your computer if you normally wear varifocals. The computer pair should be single-focus so that as you move your eyes around the screen, it all stays in focus.
No its not necessary to have single focus lenses for a computer prescription. A good optometrist will be able to give you a varifocal (Progressive) lenses in your computer prescription. Typically this is simply just an offset adjustment to your normal prescription. For a "computer prescription" as it is often called in the US, the focal range is anywhere from about 10-20 feet down to 6 inches, depending on your eyes. This is much more useful than a fixed focus lens because you can actually work in a normal office environment without everything being out of focus beyond your desk, or having to constantly change your glasses. The sweep spot of a varifocal is much wider at to bottom for computer presciption than it is on typical varifocal lens designed for every day use. Consequently much more of your screen remains in sharp focus even towards the periphery than would be the case. This "sweet spot" of focuse is typically a inverted triangle area, (or as my doc says: Picture a woman's bikini bottom), wider at the top than at the bottom. It can be very narrow at the bottom for normal use glasses. This is forced wider for Readers or Computer glasses. This technology is at the limit of current lens grinding capabilities, but future laser grinding may allow clear focus on all portions of the lens. Its important to let your doc know about your working environment. I had my wife snap a photo of me at my desk with my twin monitors at arms length, and showed that to the optometrist. He said he wished he could get that from all his patients. -- _____________________________________ ---This space for rent--- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org