I carry about about 3 pairs of glasses with me; sunglasses, reading/computer glasses, and regular all distance glasses.  I used to carry the glasses in cases, despite all the room they took up.  I've now switched to these bags and I've been extremely happy.  The bags are compact, can be used to clean glasses, and can hold other small items that you may not want scratched.  The drawstring allows you to almost completely close the bag.  My only concern is longevity as the fabric is a little thin.  If/when one of them tears on me I'll update the review.

A note on shipping, I ordered 5 at once and I got a discount on the shipping costs for the additional bags.

UPDATE: I've been using these bags for a while (more than a year) and none are even close to wearing out.  A great buy.