Ergonomics - iPhone Game Blueprints - page 73

Photosensitive epilepsy
Photosensitive epilepsy ( PSE ) is a form of epilepsy in which the patient is very
sensitive to various visual stimuli such as moving patterns, blinking backgrounds, and
flashing lights; in extreme circumstances, any of them can cause seizures. As you
see, the list of stimuli includes some elements that can be seen in modern video
games; the game screen flashes all the time when a dynamic scene is displaying.
There are a lot of flares, explosions, flickering particles, blinking text alerts, back-
grounds with regular patterns of texture moving quickly, and so on. This is why some
game situations of poor conditions—depends on the time spent during the game ses-
sion, lighting conditions, distance to the screen, sleep deprivation, emotional state,
hunger, thirst, and many more—can cause a seizure. For such cases, there is a spe-
cial term called Video game-induced seizures ( VGS ).
According to the article Stimulus Overload written by Joshua Cox (NREMT-P) and
Eric T. Richardson (MD) published in Jems magazine, video game epilepsy causes
seizures in the young and old. It states the following quote:
"It's known that PSE is more prevalent in people aged seven to nineteen, with more
males affected because they tend to play video games more than females. Those af-
fected report seeing an "aura" or feeling particularly odd sensations prior to the
seizure"
Happily, the new technologies make the problem less vexed. Because the modern
LCD displays, based on technology different from the old CRT monitors, reduce the
chances of seizures but do not exclude it completely.
Although there is not much information about seizures caused by mobile games,
it is better to have some thoughts about the players with PSE. First of all, try to
think about all the scenes in the game with flickering elements, especially if they
are large. The most problematic are the various blinking backgrounds, which can
cause the stroboscopic effect. It is not necessary to remove all the flashing effects,
but you need to adjust their frequency. The Epilepsy Society (visit their site at ht-
tp://epilepsysociety.org.uk ) informs that the potentially dangerous range lies between
3 and 30 flashes per second. Some useful information can also be found in the article
Web Content Accessibility Guidelines (WCAG) 2.0 published by World Wide Web