Saturday, May 28, 2011
Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. This means that instead of light being scattered in all directions in more usual ways, reflected light generally travels in a more horizontally oriented direction. This creates an annoying and sometimes dangerous intensity of light that we experience as glare. When you wear polarized sunglasses, that glare is eliminated and clarity is greatly increased.
Tuesday, May 24, 2011
Often what people don’t realize is that there are about 300 different brands of progressive lenses and they do not all work the same. The challenge with progressives is that the reading area of the lens is not very wide. And on each side of the usable area is distortion and motion that give you sensations that you “eventually” adapt to. In order to have success with progressive lenses, you have to understand and accept the visual system that it forces you to live within and you have to be able to adapt to the sensations it gives you. The difference between some lenses and others is that the better lenses have wider fields of vision and less peripheral distortion. Of course, they need to be fit and manufactured properly.
First of all, they should either be on your face or in a case.
Secondly, the safest most effective way to clean them is to first rinse the glasses under the faucet to remove dust and dirt off the lenses. This is the primary reason they get scratched. Next, put a little amount of dishwashing detergent on your fingers and apply to each lens washing them gently. This will do a great job at cleaning without scratching. When you are done washing, rinse the glasses under the faucet again using your fingers to feel when all the soap is off the lenses. Shake much of the water off the lenses and blot it dry with a soft and absorbent paper towel.
If you are out and about and you can’t clean your glasses like this, blow as much of the dust and dirt that you can off the lenses and rub off any smudge you might have with an appropriate cleaning cloth. Be careful - if you have dirt on the lens, you will grind it in with the cloth causing it to scratch.