staff@slashgear.com (Rahul Srinivas)
2024-04-03 14:38:52
www.slashgear.com
Have you ever noticed how brightly colored objects become less colorful — almost turning black and white — when inside a dimly lit room or when it’s dark? While humans have long been aware of this phenomenon, the cause was only investigated in the 1800s after Czech anatomist Jan Evangelista Purkyně decided to dig deeper. He eventually deduced that this difference in perception of color occurs because the human eye switches between two different systems depending on the amount of ambient light.
Purkyně’s theory would eventually be proved right after the discovery of two types of photoreceptor cells called rods and cones that the human eye uses. We now know that cone cells are primarily active during the day. The rod cells, on the other hand, become active at night and have evolved to improve our vision in the dark.
Our brains have adapted to switch between these two systems at dusk (and dawn). Interesting things happen during this transitional phase, however. Since both rod and cone cells become active simultaneously during this phase, it results in a hybrid-style color perception. This effect is barely noticed in typical sunset and sunrise events because of the gradual manner in which the transition takes place.
However, during solar eclipses, this transition happens faster than our brains can comprehend, leading to what we today know as the Purkinje Effect.