Spending more time in the great outdoors early in life offers some form of protection against visual problems later in adulthood. Findings of a new study have revealed that additional exposure to sunlight can help ward off nearsightedness later in life.
For the new study published in the Journal of the American Medical Association - Opthalmology, Katie Williams, from King's College London, and colleagues involved 371 individuals with nearsightedness and 2,797 without the condition, who were at least 65 years old.
Exposure To Sunlight And Risk For Nearsightedness
Nearsightedness, also known as myopia, has dramatically increased in the United States and in other parts of the world in the past few decades. Spending more time outdoors, however, may reduce risks.
Williams and colleagues found that exposure to the sun's ultraviolet B (UVB) radiation between the ages 14 and 29 years old was linked to reduced risk for developing nearsightedness during adulthood.
Participants of the study who had the most UVB exposure when they were teenagers or young adults had about 30 percent less likelihood of developing nearsightedness later in life than those who had the least exposure.
"This study suggests lifetime exposure of UVB is associated with reduced myopia in adulthood. The protective association is strongest with exposure in adolescence and younger adult life and with increasing severity of myopia," the researchers wrote in their study, which was published online on Dec. 1.
Visible Light Possibly Reduces Risk For Myopia
The researchers, however, did not find a clear explanation for their findings. Although people get a boost of vitamin D when they get exposed to sunlight, the researchers did not find an association between levels of Vitamin D and nearsightedness.
Ian Morgan, from Australian National University who was not involved in the study, said that exposure to the so-called visible light could contribute to reduced risk for nearsightedness.
"UVB here seems to be a proxy for simply spending more time outside. The current thinking is that the brighter light outside stimulates a release of dopamine from the retina and that dopamine slows down the growth of the eye, preventing myopia," Ohio State University College of Optometry professor Donald Mutti said.
Danger Of Spending Too Much Time Outdoors
Exposure to too much sun is known to have unwanted health consequences as well. Despite dangers of skin cancer, experts still recommend that parents encourage their children to spend more time outdoors. Kids, however, need to get protection from the sun in the form of using hats, sunscreen and sunglasses.
