From LifeHacker: The Correct Way to Clean Eyeglasses....

The Correct Way to Clean Eyeglasses:
We've all done it. When our glasses are smudged up we reach for the corner of our shirt and clean them off. You probably even know that's the wrong way to clean glasses, but you do it anyway. But you don't need special sprays and microfiber cloth to clean glasses the right way, the Wall Street Journal says you only need kitchen soap and a normal cotton cloth.
The reason your shirt is terrible for cleaning glasses is because it's likely filled with dust, and that scratches the lenses. Otherwise, any old piece of cotton will do, and regular old kitchen soap is far better than those cleaning solutions you get at the optometrist:

The AOA recommends washing glasses every morning, paying special attention to the frames and earpieces, where hair product and makeup tend to rub off. Whatever you do, don't use the most handy form of water to clean your lenses. "Some people use spit, but don't," urges Dr. Geist. Though dirty glasses won't cause an eye infection, saliva "is not the best hygiene method, and it just won't work very well," she says. Soap, warm water and a dry cloth are all you need, once a day, to keep glasses optimally clean and functional.

You also shouldn't use anything with ammonia, bleach, vinegar (although it's great for drinking glasses), or window cleaner because those chemicals strip away the coatings on your glasses. Keeping your glasses in optimal shape is really easy when you do it right. That should be just enough to keep those fancy new computer glasses in optimal shape too.
The Best Way to Clean Your Glasses | Wall Street Journal
Photo by Daniel Novta.