One of the things that happens to your eyes as you age is that the lens of your eyes yellows, in turn reducing the ability of your retina to absorb blue light. Blue light is needed to activate the production of melatonin that helps you sleep. A new study shows this is a common problem associated with poor sleep quality as individuals age.

"The strong link between lens yellowing and age could help explain why sleep disorders become more frequent with increasing age," said Line Kessel, M.D., Ph.D., the study's lead author. "The results showed that while age-related lens yellowing is of relatively little importance for visual function, it may be responsible for insomnia…sleep disturbances remained significant even after we corrected for age, sex, diabetes mellitus, smoking and the risk of ischemic heart disease.”