Illinois Vision Certification Practice Test

What does the term "refraction" refer to?

1. Reflection of light

2. Diminishing light

3. Bending of light

4. Diffracting light

The correct answer is: Bending of light

The term "refraction" refers specifically to the bending of light as it passes from one medium to another, such as from air into water or glass. This phenomenon occurs because light travels at different speeds in different materials. When light enters a new medium at an angle, it changes speed, resulting in a bend in its path. This bending is crucial in optics, as it is the principle that allows lenses to focus light, enabling the formation of images in instruments like glasses, cameras, and microscopes. It plays a significant role in understanding how vision works and how to correct refractive errors in the eye, which illustrates its importance in the field of vision and optical science.