Blue light emitting from screen of digital devices produces toxic molecules in retina which lead to macular degeneration – visual impairment.

Digital devices like smartphones, tablets and laptops use red, green and blue light to give a colorful visual on their screens. Blue light has short wavelength and more energy compared to other colors. This gives blue light more penetration power than other lights. 

Retina, light sensitive part of eye, has photo-receptor cells which requires retinal molecules to sense light and signaling to brain, enabling us to see. Retina unable to block or reflect most of the blue light. Blue light triggers a chain of reactions when exposed to retinal. This produces toxic molecules in photo-receptor cells, which damages their membrane and kill the cells.

Kasun Ratnayake, Ph.D. student at University of Toledo (US) who was involved in this experiment, said: “Photo-receptor cells do not regenerate in the eye. When they’re dead, they’re dead for good.”

“The retinal-generated toxicity by blue light is universal. It can kill any cell type.”

Dr. Ajith Karunarathne 

Later studies shows “alpha-tocopherol”, a natural antioxidant found in eyes and body stops cells from dying. It fails to work in aging cells or those whose immune systems have been suppressed. According to Dr. Karunarathne, “That is when the real damage occurs.”

Macular disease is caused by deterioration of light-sensitive cells in retina. This is used to be a age-related disease. But, due to excessive use of digital devices, few cases are seen in smaller age as well. 

Cure For Blue Light:

Dr. Karunarathne suggests the use of sunglasses while using smartphones and laptops. Wearing sunglasses can filter both UV and blue light outside and avoid from using digital devices in dark. Blue light is dangerous for retina in dark.

Some cell manufacturing companies have start introducing an option for filtering the blue light from cell phones for safer use. This option is usually called “Eye Protection” depending on the manufacturer.

Other options include use of glasses with amber or orange colored lenses, which helps to filter out the blue light. 

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