A coating for lenses in glasses may help night workers to avoid hormone problems caused by exposure to certain types of light, the makers claim.
Canadian publication the Globe and Mail reports how researchers in Toronto have developed the coating, which can be worn on prescription lenses as well as non-corrective ones.
Exposure to certain wavelengths of light at night can alter hormone levels, such as reducing the volume of anti-cancer hormone melatonin and upping the stress hormone cortisol.
But Dr Robert Casper, who led the Samuel Lunenfeld Research Institute team, told the paper that only a small number of wavelengths in the blue section of the light spectrum cause such problems.
The coating, which has a yellow hue, is said to block these wavelengths.
In 1999, University of London psychologist Dr Glenn Wilson said that wearing sunglasses could help people to feel more attractive.
The BBC reported his belief that men can appear unpredictable and threatening through covering their eyes in such a way.
by Emily Tait