Cataracts impede optimal vision. The cloudiness of the natural lens creates a physical risk, especially for seniors who are already at a higher risk for falls and other accidents. But sleep? Is it possible that having cataracts could be an obstacle to a good night’s sleep? According to a few studies, there may be something to this theory.
Let’s Look at the Evidence
Researchers at Nara Medical University in Japan conducted a study to observe the sleep patterns of patients who had had cataract removal surgery. What researchers focused on was the clouded lens and how this prevented light from reaching the area of the brain in which the body clock is set.
Just over 1,000 men and women participated in this study. Each participant in the study wore a sleep tracker that recorded not only the duration of sleep but the quality. Researchers discovered that the study participants who had undergone cataract removal slept longer and better than other participants.
This Japanese study was preceded by a smaller observation of just 400 people who had undergone cataract removal. This earlier study reported that 28% of participants experienced poor sleep one-month post surgery. By 9 months after cataract removal, though, only 15% of the study participants reported poor sleep.
How can this be?
The body learns its sleep rhythm through a light. Specifically, through a 24-hour cycle of light and darkness. Blue light enters into the eye and is transferred to a part of the brain that sets the sleep pattern. It is thought that blue light cannot adequately permeate the clouded lens to reach this part of the brain, and therefore the sleep rhythm cannot be set appropriately.
There is another factor shared amongst insomnia and cataracts that could be an important aspect of both prevention and treatment for each condition, and that is melatonin. Melatonin is a hormone that has been identified as a natural sleep aid. Sometime in our 40’s, the body slows its production of this hormone. Within a few decades, we could have very little melatonin to speak of in the body.
In addition to sleep, melatonin is also a vital nutrient for eye health. This hormone prompts the production of glutathione, another antioxidant that fights free radicals in the proteins in the eye.
Roholt Vision Institute provides cataract removal surgery and several other services. Speak with a friendly member of our staff in an office near you to schedule your consultation and eye exam.