How a Flicker Causes a Seizure

Preliminary reading: Laser Cascade and Too Much Light

We know that some people can have seizures brought on by flashing lights. Previously, I tried to tie this to seasickness. Let’s explore this concept from another perspective. 

What happens physiologically when a light turns on? Your pupils contract. Then as the light turns off, your pupils dilate, controlling the amount of light that enters the eye. If we put the person in front of a strobe light, the cycle of light/dark could outpace the mechanism designed to keep excess light out. At very least, there is a lag time between the light, and the eye’s adaptation to the light. This process, over the course of seconds, gains photons in the eye. It simply cannot keep up with the rate of change.

Factors that are pertinent here are max pupil size, resting pupil size, and speed of contraction. With these three factors we can accurately draw a curve for the pupil size over time. 

IMG_6396
Here’s how I see it.

In normal individuals, this is not an issue. But in with people with epilepsy, they already exist at a higher energy state. A bunch of extra photons could push them to their charge threshold. 

A seizure is the body’s built in mechanism to remove excess electric charge. 

Sources:

  1. https://www.nature.com/articles/s41598-018-23265-x
  2. https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1528-1167.2011.03137.x
  3. https://www.medpagetoday.com/neurology/seizures/3552