What does contrast sensitivity primarily relate to?

Contrast sensitivity primarily relates to the ability to perceive differences in luminance between an object and its background. It measures how well a person can detect edges and shapes based on variations in light levels, which is essential for distinguishing objects in various lighting conditions. This skill is crucial for tasks that require sharp vision, especially in environments where light contrasts are minimal.

While color differentiation involves recognizing colors and can be important in visual perception, it does not directly relate to the ability to detect differences in luminance. Movement detection pertains to the ability to notice motion, which, while a key aspect of visual processing, does not specifically measure sensitivity to contrast. Peripheral vision capability refers to the ability to see objects outside of one's direct line of sight and is also separate from contrast sensitivity. Thus, the most accurate representation of what contrast sensitivity entails is the capacity to notice luminance differences.