If aching joints, thinning hair, or even fading memory and hearing weren't enough, science has now proven that one more thing can be attributed to aging-sleep disturbances and insomnia.
As we age, the lenses of our eyes also age, as well as begin to yellow. This gives a whole new meaning to the term ‘golden years’. This yellowing of the eye lens reduces the amount of blue light from reaching our retinas - exactly the type of light needed to regulate our circadian rhythm, or body clock.
Without enough of this wavelength of light reaching us, our sleep schedule may become deregulated. In addition, this lack of blue light can also cause sleep disturbances. This means if you are able to fall asleep, you may wake up more frequently during the night.
The body clock generally runs smoothly on its own, however, it does need nudging from time to time to keep it on track. Sunglight helps to keep the body closk synchronized. Light that enters through the eye communicates with the brain, which then triggers the brain to adjust itself to the environment. When regulating sleep, the brain releases melatonin in the evening when light is fading to prepare us to fall sleep. Then, it releases cortisol in the morning when light is bright, so we become more mentally alert. Yellowing eye lenses as we age throw a wrench in the whole machine.
It is said that by age 45, only 50 percent of the light we need to fully stimulate our body clock gets filtered in through our eyes. By age 55, this drops to 37 percent. By the age of 75 only a small 17 percent of the light we need filters in. Because of these massive changes that go on in the eyes as we age, it is important that adults expose themselves to as much bright sunlight as possible. If being outdoors is impossible, bright indoor lighting should be used.
For some, this may be another good reason to agree to the cataract surgery your doctor is recommending. The possibility that it could eradicate your insomnia may be the deciding factor. After surgery, more light is able to filter into the eye, which means an increase in melatonin production and sleep that may be easier to come by.
The human body is a wonderful machine with its built in circadian rhythms. It runs on its own and we don’t think about it. We get up, go about our day, come home, wind down and go to sleep. We don’t really give too much thought to everything going on inside of us to help make that happen. That is, until a problem with our body’s rhythm develops an issue like insomnia. But who knew that it may simply be a result of yellowing eye lenses?
Martin is the creator of Insomnia Land’s free two week online sleep training for insomnia. Over 3,000 insomniacs have completed his course and 96 percent of graduates say they would recommend it to a friend.
Kessel, Line et al. 'Sleep Disturbances Are Related To Decreased Transmission Of Blue Light To The Retina Caused By Lens Yellowing'. SLEEP (2011): n. pag. Web. 29 May 2015.
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