system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come the same prescription for eyeglasses produces thick "coke bottle" lenses can be used for paper thin contacts?
gpt
The glasses are pretty far from your cornea (the lens on the front of the eye.  Contact lenses are, or course, in contact with the cornea.  A much thinner lens can bend the light the required number of degrees because the light hasn't spread out to an aviator's eyeglasses sized area before the lens has to capture it.