How do glasses help us see? - Andrew Bastawrous and Clare Gilbert

View full lesson: http://ed.ted.com/lessons/how-do-glasses-help-us-see-andrew-bastawrous-and-clare-gilbert Today, glasses help millions of people with poor vision be able to see clearly. But how? Andrew Bastawrous and Clare Gilbert help unravel the answer by explaining refraction — the ability of a transparent medium, like glass, water, or the eye, to change the direction of light passing through it. Lesson by Andrew Bastawrous and Clare Gilbert, animation by Andrew Foerster.