Light is, undoubtedly, a vital part of human existence, but too much of eye exposure to light can lead to steady vision degeneration with age, according to an Australian.
Professor Jonathan Stone from The Vision Centre at University of Sydney led the research. The team claims that their research has enough proof to convince that cumulative light exposure in an individual's lifespan can result in weak vision and the loss may further continue with the aging process.
"We're born with about 150 million light-sensitive cells – known as photoreceptors – in each eye. All through our life we lose these at a steady rate of hundreds every day, but some people lose them much faster than others, with the result that they go blind – sometimes quite early in life," said Stone.
"These light-sensitive photoreceptors are remarkably tough, and most people still have 100 million or so left by the time they reach their 70s or 80s," Stone added. He explained that the photoreceptors cells begin to lose in late stage of life, leading to dimmed eyesight or even complete vision loss.
According to Stone, "The eye contains a great many highly-specialized genes, which affect no other part of the body, and these in turn produce many random mutations. It is these mutations which make the normally gradual degeneration of the retina more acute in some people than in others."
If light exposure is limited all through the life, particularly in middle and old age, then these photoreceptors may last longer through the older years. The research team suggested sunglasses as one effective way of cutting down the exposure.
Stone commented, "Most sunglasses will reduce by 25-50 per cent the amount of outdoors light from entering the eye and, knowing what I now do as a result of years of work in this field, I never go outside without my sunnies."
Even though, some exposure is essential to avert myopia and eyeball distortion in kids, researchers believe that too much exposure could well be damaging and irreparable. Being mindful to the amount of light exposure in childhood and adolescence years, can be rewarding in later years of an individual's life.
"However our research clearly indicates that there are also environmental factors at work which cause the eye to lose photoreceptors more rapidly, especially in people with a certain genetic makeup," said Stone.
To some extent, a protective antioxidant-rich diet can slow down this age-specific vision degeneration. While researches are on ways to fix damaged vision, wearing a sunglass outdoors might just be equally good.
Stone noted that "It appears that by managing the oxygen levels in the eye, through diet and other methods, we can slow down and possible even reverse the loss of photoreceptors, and we are planning a clinical trial to test this idea."
