Our increased use of smartphones and other digital devices has sparked much debate about the potential hazards of “blue light” to eye health. BBC’s Watchdog highlighted the issue in a recent undercover investigation into the selling of special lenses designed to filter out blue light.
The programme showed optical staff from two chains of high street opticians stressing the dangers - including one employee who warned that blue light “kills” retinal cells at the back of the eye, causing macular degeneration. So, how concerned should you be about the risk from blue light?
What is blue light?
Blue light forms a small part of the visible light spectrum. It is produced naturally by the sun and artificially by low energy lighting and electronic devices like smartphones, computers and tablets.
Can blue light damage sight?
Some studies do show that certain wavelengths of blue light in high doses can harm retinal cells. However, there is no reliable scientific evidence that the low levels emitted by digital devices can cause permanent damage. In fact, one leading expert, featured on Watchdog, demonstrated that the amount of blue light emitted by a smartphone represented less than 1% of the safe level.
The ultraviolet risk
However, not all wavelengths of light can be considered harmless. Ultraviolet (UV) rays in sunlight have been clearly shown to damage the lens and retinal cells inside your eye, significantly increasing your risk of developing cataracts and macular degeneration. Compared to blue light, there are more compelling reasons to consider lenses that block out UV rays - particularly if you spend a lot of time outdoors. These include many types of reflection-free lens, as well as transitions and approved sunglass lenses.
If you have any concerns about blue light or UV protection, consult your optometrist for advice.