Why? To help developers in pre-production have the necessary “at-glance” aspects of game design to pay attention to with the goal of photosensitivity awareness.
Contact: LianaAccessibilityLine@gmail.com
Quick facts:
Avoid rapid flashing, especially in high contrast environments (I.e., the most dangerous combination is white on black, red and white on black, red on black. See also pale grey)
Avoid flashing greater than 3 Hertz
Flashing lights should be placed in the distance from one another with flashes set at the same time to avoid accidentally recreating a harmful flash sequence above the recommended Hertz with non-synced patterns, if possible. This won’t always be possible with the creative vision. That’s OK
Also consider transition effects, versus aggressive flash on/off.
Fade in/Fade out, wavelength animation, etc.
For different types of triggers and epilepsy, including photosensitive-prone, feel free to mosey over to this resource that I wrote at Game Informer as a “Epileptic’s Guide to Gaming” in conjunction with the Epilepsy Foundation of America.
Luminance flash failure
Definition: A flash is defined as a 10% change in luminance (where 100% is the maximum luminance of a white screen)
The darker luminance value should be below 0.8.
Failure criteria:
Flashes occur too frequently (approximately more than 3-per second).
Flashes take up a certain amount of the screen (approximately 20% or more).
Lower-intensity flashing can also cause a negative neurological reaction (or a Harding failure) if it’s continued for an extended period of time.
How to address:
Reduce the contrast between the brightest and darkest parts of flashing effects.
Reduce the frequency of the flashing.
Decrease the size of the flashing animation.
Red flash failure
Definition: A red flash requires a lower change in luminance than a normal flash. Specifically, it applies when either extreme of the flash is a saturated red. For the tech nerds (waddup): (R/(R + G + B) >= 0.8).
A flash here is defined when the change in the value of (R-G-B) × 320 is greater than 20.
Failure criteria:
Flashes occur too frequently (approximately more than 3-per second).
Flashes take up a certain amount of the screen (approximately 20% or more).
Lower-intensity flashing can also cause a failure if it’s continued for an extended period of time.
How to address:
Desaturate the red coloring.
Reduce the contrast between the brightest and darkest parts of the flash.
Reduce the frequency of the flashing.
Decrease the size of the flashing.
Spatial pattern failure
Definition: Alternating bands that have high contrast define a spatial pattern.
Failure criteria:
The difference in contrast is greater than 10%.
The pattern takes up a large part of the screen (20% or more).
How to address:
Reduce the contrast between the bands
Decrease the size of the pattern.