on 3/7/2009 2:08:31 PM
Light travels at a speed of 186K Miles/ Second.

on 3/7/2009 7:27:13 PM
Purchasing lenses for your eyeglasses...do not buy BIG lenses. It's ok, I'll tell you why haha. The strength of the lens weakens as u get further away from the middle. Hence, if the lens is made to fit to have u look through the middle.....if u'r glasses are shifted or moved you will not b using the same prescription (rx), assigned to u.

on 3/7/2009 7:29:56 PM
An update to my knowlege: the cornea blocks UVC light rays. Sunglasses block UVA and UVB light rays.

on 3/8/2009 3:42:55 AM
To apply AR Coating (Anti Reflective), or not. Yes you can/ should. When ordering rx sunglasses (prescription), have a/r coating applied to the back of the lens. Have them also applied to Transition (photocromatic) lenses, and even Polorized Lenses. Re: cuts down the glare and halo-effect. Yes, Polarized lenses are specifically made to reduce glare...yet a/r coating adds better visual acquity (ie visual quality).

on 3/10/2009 3:04:32 AM
Going back to the subj of AR Coated Lenses (Anti-Reflective). For those of us that love detail and need to know, or even should know. A single layer of coating is thinner than a ray of light! AR Coating is measured in Angstroms....one tenth of ray of light (nm or nanometer). Hence an Angrstrom is 1/10th the thickness of light; light is measured in nanometers. In other words, a single layer of AR is 1/10th of a billiionth of a meter!!!

on 3/10/2009 3:12:57 AM
The EYE. The eye is normally one inch long. The age we tend to need reading glasses is 40. The power of the eye is measured in D (Diopters). The eye is approx 63D. LENSES are also measured in Diopters.

on 3/10/2009 3:54:21 PM
AR Knowledge, one layer of coating is first applied to one layer of either chromium or slilicon monoxide. This glue-type substance allows the AR coating to stick' to the lens.

on 3/12/2009 1:44:03 AM
DYK (Did You Know), glare or light that is reflected tends to be 10% brighter than normal light. So....when deciding whether or not to buy reg sunglasses or polarized sunglasses, buy polarized sunglasses. As prev commented, Polarized Lenses reduce glare.

on 3/16/2009 8:02:49 PM
Did someone out there think about the speed of light recently and what-the-hell does this guy really know? Anywho.....eyeglasses are primarily made with either Plastic lenses or Polycarbonate lenses. Light passes through plastic lenses faster than Polycarbonates.

on 3/25/2009 4:45:06 AM
Reading glasses. Do Not Ever buy pre-fabricated glasses from a drug-store etc. These are not made to have to optical ctr of the lens lay in front of u'r pupil!!!