Wednesday, March 20, 2013

Answer To Question 218

A218: Dark adaptation consists of the physical and chemical changes in your eyes that allow them to see well in the dark. Physically, the pupils of the eyes open wider (this happens quickly); chemically, slower changes occur in the eyes (which takes 10-20 minutes). It takes about 20 minutes for your eyes to completely adapt to darkness. Once your eyes become accustomed to the dark, even a momentary flash of white light can ruin it and your eyes will have to adapt all over again.

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