I heard the other day there was a new machine
for eyeglass prescriptions.
Evidently the patient looks into it at an
object (say a small model house) and the

Can someone help refine the equation for Focal Length and Dioptre.  I
am looking for the optical equation to calculate a lens's Dioptre at
home if the light source is not at infinity.
I went through the info in a Sci.Med.Vision thread to calculate the

I am a computer programmer and as such, 90% of my 8hr work day is
spent staring at computer screens.  After I finished college a year
ago and starting working full time I noticed that after a few hours of
working in front of computers my eyes start to hurt and my vision will

CORNEAL COLLAGEN CROSSLINKING WITH RIBOFLAVIN (C3R)
                      AS PER C3R PROCEDURE IS CONCERNED , IT IS
VERY SAFE NON - INVASIVE PROCEDURE AS COMPARE WITH CORNEAL GRAFTING,
RESULT ARE NOT IMMEDIATE, BUT THERE IS CORNEAL THICKNESS IMPROVEMENT

I'm hoping for some advice to help me order a pair of specs for computer
use from an online store. I've got a recent prescription for reading
glasses that are great for focusing at around 35cm, but not very suitable
for computer work:

Who is wearing these new (in the USA) silicon hydrogel contact lenses now?
Who is prescribing them for patients? What have the results been like? How
do they compare with Night&Day and Purevision? Has anyone been wearing them
overnight? (Apparently they have been approved for EW ...

X-MASS - YULETIDE
A PAGAN FESTIVAL
(which is actually condemned by Christ)
CHRIST'S OPINION of SANTA CLAUS and YULETIDE, as expressed by HIS

My daughter is considering applying to the following schools
SUNY Optometry in NYC
Pennsylvania College of Optometry in Elkins Park, PA
New England College of Optometry in Boston

Scientists at Schepens Eye Research Institute, an affiliate of Harvard
Medical School, have discovered a simple and inexpensive way for
patients with retinal and other eye disease to keep track of changes
in their vision loss.

Are most basic plastic lenses made of CR39, or is there another basic
plastic that's significantly thicker? I've just bought some glasses and
I think the lenses are polycarbonate because the chromatic aberration is
quite severe and they're definitely thinner than my old glasses ...

I have a bit of advertising from Perle Vision touting EasyView lenses. The
blurb goes on to say "Progressive lenses can be a workout for your eyes."
(No sh.t! I'd never have guessed.) Anyway, goes on with self-praise, saying
the eyes focus more naturally. Nice to know after I just ...

Is it possible to calculate the lens thickness from my prescription
using Hoya 1.60 Index and 1.70 Index Eyry lens. The lens will be
reglazed into a pair of Hoya Rimless Glasses.
Right Lens:

My 14 year old son has been recommended to wear his glasses for all
activities and he is reluctant to do that.  The prescription, his first, is
OS    -.50
OD    -1.25   -0.5 x 135

Are there any references (peer-reviewed) out there reporting an
"average" visual field in degrees?  From reading the many great posts
on the list, I've learned that the visual field depends on many
things, including physical obstruction from the nose, eyebrows, etc.

I'm curious. There's a Canadian politician who wears dark glasses all the
time, including indoors. What disorder would necessitate this practise?
Thanks for any replies.