Blue Light Eye Damage

"Blue light is the most energetic portion of the visible light spectrum," says ophthalmologist Bernard Godley, of the Retina Foundation of the Southwest in Dallas.

"It's less energetic than UV radiation but it also has the ability to penetrate into tissue and cause cellular damage."

Godley, working with an international team of researchers, has shown that chronic exposure to blue light damages retina cells in the lab — the same cells involved in age-related macular degeneration (AMD), the leading cause of blindness untreatable vision loss and legal blindness in the U.S. for people over the age of 60.

Godley and his colleagues reported in The Journal of Biological Chemistry that blue light alone can damage the power houses of the retina cells, called mitochondria, and in particular the DNA of these energy-producing structures, suggesting that any cells exposed to visible light — including skin cells — may sustain damage.

The researchers exposed cultured retina cells to blue light for up to six hours in the lab. Compared to cells that had been kept in the dark, they saw a loss of mitochondrial activity in the illuminated cells after only 6 hours and this loss became greater with increasing time.

Using a genetic technique called polymerase chain reaction they found that light exposure significantly damaged the DNA of the mitochondria after three hours, but by six hours the body's natural DNA repair process had kicked in, reducing the amount of damage.

"We confirmed that these changes, this damage, was caused by free radicals, which were generated by the mitochondria themselves. Evidence suggests that these changes may play a role in cellular aging, and in age-related diseases such as macular degeneration," says Godley, suggesting that, "blue light may contribute to the aging process."

But Janet Sparrow's ophthalmology research lab at Columbia University Medical Center's Edward S. Harkness Eye Institute in New York says the most important damage from blue light involves pigments that accumulate only in the retina cells. "There have to be molecules in the cell that… are able to very efficiently absorb wavelengths in the blue region," she explains. "And this pigment, we now know, is able to initiate phototoxic reactions, that is it can absorb light and initiate reactions in the cell that are damaging."

AMD, which has robbed more than 10 million Americans of some or all of their vision, causes the deterioration of the cells in the center of the paper-thin, light-sensitive retina at back of the eye — the macula — that focuses the images we see and sends them via the optic nerve to the brain. This results in the progressive loss of central vision, affecting a person's ability to read, drive, recognize faces or colors, and generally see objects in fine detail.

In some cases, AMD advances so slowly that people notice little change in their vision, and currently available treatments can delay, and sometimes prevent, the progression of the disease, leaving the person with some vision, but there is no cure

To help protect against damaging light rays newer yellow-tinted lens implants can be used, that will replace the UV light-absorbing lenses that have been used since the 1980s. "This is an option that will provide additional protection that I think will be beneficial," says Godley. But these lenses may reduce people's vision in low light, so that option should be discussed with your eye doctor.

It will also take more research to determine how much blue light exposure in nature will cause damage. "The actual dose-response relationship represents a gap in our knowledge and a potential direction for future research," Godley says.

Meanwhile the researchers say that it's easy for us to protect ourselves from blue light by wearing yellow-tinted sunglasses that filter out both ultraviolet and blue light.

This material is made possible by the the Journal of Biological Chemistry and the American Society for Biochemistry and Molecular Biology.