What describes what occurs to light when it passes through materials like glass?

When light passes through materials such as glass, it undergoes a phenomenon known as refraction. Refraction occurs when light travels from one medium to another, resulting in a change in its speed and direction. This bending of light is a fundamental concept in optics and is responsible for various optical effects, such as the way lenses focus light to form images.

In the case of glass, which is denser than air, light slows down as it enters the glass, causing it to bend towards the normal line (an imaginary line perpendicular to the surface). This property of glass can be utilized in various applications, including eyeglasses, cameras, and other optical devices, where precise control over light is essential.

Other phenomena related to light, such as reflectance (the bouncing of light off surfaces), diffraction (the spreading of light waves when they encounter an obstacle), and absorption (the uptake of light by materials, converting it to other forms of energy), do not specifically describe the behavior of light as it transitions through the boundary of materials like glass. Therefore, the correct description of what happens when light passes through glass is refraction.