Refraction is the bending of light as it passes through different mediums. This occurs because light travels at different speeds in different mediums, causing it to change direction. This effect is most noticeable when light passes from air into water or glass, where the light is bent towards the normal (an imaginary line perpendicular to the surface).
Reflection is the bouncing of light off a surface, while refraction is the bending of light as it passes through a medium. Reflection occurs when light hits a surface at an angle and bounces off at the same angle, while refraction occurs when light travels through a medium that causes it to change direction.
A lens is a curved piece of glass or plastic that is used to refract light. It works by bending light as it passes through the lens, causing the light to converge or diverge. This allows the lens to focus light and form images. Convex lenses (thicker in the middle) converge light, while concave lenses (thinner in the middle) diverge light.
The color spectrum is the range of colors that make up white light. This occurs because white light is made up of all the colors in the visible spectrum. When white light passes through a prism, the different colors are refracted at different angles, creating the rainbow of colors we see. The color spectrum can also be seen in rainbows, where water droplets act as tiny prisms.
A convex lens is thicker in the middle and thinner at the edges, causing light to converge. It is commonly used in magnifying glasses and eyeglasses to correct farsightedness. A concave lens is thinner in the middle and thicker at the edges, causing light to diverge. It is used in glasses to correct nearsightedness.