If you have eyeglasses that are no longer useful for you it doesn't mean they are no good. Consider donating them to an organization where they are given to someone who can use them. Check your Municipal Buildings and Libraries to see if they offer a drop off bin for used eyewear. Also check with your eye doctor to see if they are involved in a recycling program.
Other drop off programs include:
Earth911 - Enter Eyeglasses in the Search For and your Zip Code for a location near you.