Where in the eye does refraction take place?

80% takes place in the cornea, 20% takes place in the lens. Hope this helps ;)

Most of that refraction in the eye takes place at the first surface, since the transition from the air into the cornea is the largest change in index of refraction which the light experiences. About 80% of the refraction occurs in the cornea and about 20% in the inner crystalline lens.