Steve,
This is serious business. People don't know these things. I remember how uncareful they were to measure my IPD at the place where I ordered my bifocals. I just tested them with objects at 4m distance. They make the objects look a little bigger and much sharper, but do not make them juf to and away from me. Sergio From: Steve Richfield [mailto:[email protected]] Sent: Saturday, July 28, 2012 2:29 PM To: AGI Subject: Re: [agi] Lessons for AGI from the first glaucoma reversal Alan, On Sat, Jul 28, 2012 at 11:44 AM, Alan Grimes <[email protected]> wrote: Steve Richfield wrote: > Glasses do LOTS of things besides making images sharp. They make images > larger or smaller. They introduce pincushion or barrel distortion. They > introduce differences in responses to maintain eye tracking. All of > these things "warp" your sense of where things are in your world. =\ I had to go without glasses for a week or two. When I got my new pair, they made me feel like I was 3 feet tall! =\ That is because they got your interpupillary distance (IPD) wrong. I make my own measurements using a precision steel machinists ruler and a mirror. The gizmos that most eyeglass places have are usually badly miscalibrated. Note that http://EyeBuyDirect.com has some fancy software where, if you create an account (no purchase is necessary) and enter in your photo, it computes your IPD from your photo!!! I tried it. We disagreed by ~1 mm, which sounds better than your eyeglass place is doing, unless your prescription is EXTREMELY strong. BTW, the quick test for IPD being correct is to look at an object that is ~4 meters or ~13 feet away, and flip your glasses up and down to see if the object seems to jump toward and away from you as you alternately look through your glasses, and look under them. Your present glasses would obviously fail this simple test. I suggest going back and getting them to make their glasses right. I'm a bit better now that my brain has adapted, but it was totally freaky. Now, you will have a similar hassle sometime in the future when you get proper glasses. Steve AGI | <https://www.listbox.com/member/archive/303/=now> Archives <https://www.listbox.com/member/archive/rss/303/18883996-f0d58d57> | <https://www.listbox.com/member/?&; ad2> Modify Your Subscription <http://www.listbox.com> ------------------------------------------- AGI Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/21088071-c97d2393 Modify Your Subscription: https://www.listbox.com/member/?member_id=21088071&id_secret=21088071-2484a968 Powered by Listbox: http://www.listbox.com
