CONTRAST SENSITIVITY DEFINED

In its simplest terms, contrast sensitivity refers to the ability of the visual system to distinguish between an object and its background. For example, imagine a black cat on a white snowy background (high contrast) vs. a white cat on a white snowy background (low contrast). According to the channel model of vision, size selective contrast cells are used to detect the differences between light and dark parts of an object and the background against which it is seen.

Blur Is Not The Same As Contrast Loss :: People who test poorly on the 20/20 visual acuity letter chart will experience blurred vision. Blurred vision, however, is not the same as poor contrast sensitivity. A person who has poor contrast sensitivity, due to cataracts for example, may still test well on the 20/20 visual acuity letter chart will still experience blurred, cloudy vision. Consider the image below.

By understanding the Channel Model, it is easy to see how a 20/20 score using a letter chart doesn't adequately predict how well we see in everyday life.

 

This site is regularly updated. Please check back with us often. ContrastSensitivity.net is brought to you by Vision Sciences Research Corporation, San Ramon, California.

| Home | Site Map | About Us | Vision Science |
| Contrast Sensitivity | Vision Testing | Research |
| Resources | Glossary | References |