What effect does refraction have on objects underwater when viewed through a mask?

Refraction is the bending of light as it passes from one medium to another, such as from air into water. When you look underwater through a mask, light rays entering your eyes are bent, leading to a magnification effect. This bending of light makes objects appear larger and closer than they actually are.

The reason this occurs is that light travels more slowly in water than in air, causing it to change direction at the interface between the two media. The perception of size and distance is affected because our brains interpret the information based on how light travels in air, which is different from how it travels in water.

This phenomenon can significantly impact underwater navigation and the understanding of distances while diving, making it essential for divers to be aware of this effect for safety and enhanced enjoyment of the underwater experience.