Ace the NBEO Visual Perception Challenge 2025 – See Success in Sight!

The Stiles-Crawford effect describes how the perception of brightness and color can vary based on the direction from which light enters the eye. Specifically, it indicates that rays of light entering the eye near the center of the pupil (known as paraxial rays) are more effective at stimulating cone photoreceptors compared to those entering from the edges of the pupil (marginal rays).

This phenomenon occurs because paraxial rays strike the photoreceptors in a more optimal way, allowing for more effective stimulation and signaling to the brain. The cone photoreceptors are more sensitive to light that enters along their preferred axis, leading to better visual perception when light arrives from this direct path. Consequently, under typical viewing conditions, the eye demonstrates greater sensitivity to light rays that come directly from the center of the visual field rather than from oblique angles, which tends to occur with marginal rays.

Understanding this effect is crucial in the context of vision science, as it illustrates how the structure of the human eye and the orientation of photoreceptors contribute to our overall visual experience.