Aging is not for the squeamish: skin sags, joints ache and hearing might start to go. And many seniors have trouble sleeping, which can lead to other health problems. Now research shows that a subtle consequence of aging may be responsible for the insomnia: the eye's lenses turn yellow.
The yellowing can take decades, like a page slowly turning color in an old book. But what does this color change have to do with sleep? The yellowed lens allows less blue light into the retina. And those wavelengths of light play a key role in regulating our circadian rhythm and sleep schedule.
The new study looked at 970 older adults, and found that those with the yellowest lenses also tended to report the most sleep disturbances. The findings are in the journal Sleep. [Line Kessel et al., "Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing"]
Cataract surgery replaces the aging lens with an artificial one, which can let in broader ranges of light—and has been reported to improve sleep. It may be counterintuitive, but getting better shut-eye in the golden years might mean letting more light in.
[The above text is a transcript of this podcast.]