Blue light toxicity and the eye

Several studies have been published in medical literature regarding high-intensity blue light inducing retinal cell death.

This leads to questions regarding the effect of blue light emitted from displays of smart phones, monitors, televisions, and whether this blue light has the same effect on the health of retinal cells.

One study examined this question and investigated the effect of blue light emitted from various devices. It showed that blue light increased the production of reactive oxygen species (ROS), especially with a shorter wavelength of 449 nm. The study concluded that blue light hazard from display devices might be greatly reduced if devices contained less short wavelength blue light (Moon J et al. Integr Biol (Camb). 2017;22: 436-443). Some smartphones can remove blue light from their display.

A difficulty with such studies is that they are laboratory based and not necessarily applicable to the body’s natural state.

Another study concludes that exposure to blue light in the range of 470 to 480 nm for days to weeks should not significantly increase the risk of development of eye disease. However, this finding cannot be generalised to long-term exposure (months to years). More studies are required to determine the effects of blue light on the eye (Tosini G et al. Mol Vis. 2016;22:61-72).

The natural crystalline lens of the eye grows larger and more yellow with increasing age, (i.e. a cataract forms). This results in decreased transmission of light, especially of short blue wavelength light. To address blue light toxicity, intraocular lenses commonly contain a blue light filter in the lens to mimic the natural crystalline lens absorption and transmittance properties of blue light. This prevents short wavelength blue light reaching the retina.

Controversy still exists around blue light toxicity in real life situations rather than laboratory science. Antioxidants, such as vitamin D, lutein and zeaxanthin, are useful free radical scavengers that offer protection against potential blue light induced retinal cell damage.