People with photosensitive epilepsy could soon be able to watch TV without worry. Scientists in the UK have created glasses that can block out specific wavelengths of light known to cause seizures.
It’s estimated that about one in 4,000 people have photosensitive epilepsy, and as the name suggests their seizures are triggered by light. Flashing and alternating patterns, such as those in clubs, emergency vehicles, television, movies and video games, can all be triggers if they have just the right mix of brightness, frequency and wavelength.
Now, scientists at the Universities of Glasgow and Birmingham have developed a pair of glasses that could help reduce the risk. The lenses are designed to block out almost all light with wavelengths between 660 and 720 nanometers – a region of red light that was implicated in the infamous Pokémon incident in 1997, which triggered seizures in hundreds of viewers.
These lenses contain liquid crystals that change their optical properties in response to heat. In this case, the frames of the glasses has a small circuit that heats the lenses up to 36.5 °C (97.7 °F), which causes them to reflect those particular wavelengths of red light.
The idea there is that people could wear them out and about with normal vision most of the time, but could switch them on when they want to watch TV or play video games without worrying about having a reaction.
Previous studies have used colored lenses to achieve a similar effect, but these only filtered about 50% of the targeted red light. On top of that, they don’t switch on and off, so affect the color vision of the wearer in all situations rather than just those with high-risk of seizures.
In its current form, the glasses can only work in environments of up to 26 °C (78.8 °F), so this is something that the team plans to continue working on. In addition, they want to reduce the time it takes to activate them.
The research was published in the journal Cell Reports Physical Science.
Source: University of Birmingham
