Bringing mammoths back, life on early Earth and more reader feedback

Inside the eye

A new technology called optogenetics may help restore sight for some blind people. In “Seeing the light” (SN: 5/30/15, p. 22), Tina Hesman Saey explained how scientists are recruiting nerve cells in the eye to act as light detectors.

Reader Steve Schlosser thought the light-processing machinery of the eye’s retina sounded just a bit backwards.