As you age, the lens of your eye gradually yellows, the pupil becomes narrower, and less sunlight gets through to your retina. Recent research suggests that this can disturb your body’s circadian rhythm, contributing to a broad range of health problems.
Circadian rhythms are cyclical processes that rely on light to function properly. People whose circadian rhythms are thrown off are at risk for illnesses ranging from insomnia to heart disease to cancer.
According to the New York Times:
“... [C]ells in the inner retina, called retinal ganglion cells ... are especially responsive to the blue part of the light spectrum. Among other implications, that discovery has raised questions about our exposure to energy-efficient light bulbs and electronic gadgets, which largely emit blue light. But blue light also is the part of the spectrum filtered by the eye’s aging lens.”