Long before sunglasses came on the scene, animals had evolved ways, such as shutter-like irises, to deal with the large differences in lighting that their eyes encounter. After all, many animals can see on both a starry night and a sunny day.
Two research teams have now uncovered a novel molecular mechanism that assists animals' vision. Proteins that are central to the complex light-sensing systems of the eye migrate from one part of a retinal cell to another to adjust the cell's sensitivity.
"This is a new theme" in light adaptation, says Vadim Arshavsky of Harvard Medical School in Boston, an author of one of the reports that appear in the March 28 Neuron.