Optics

Reflection

Occurs when light hits a surface and bounces back into the medium it originated from.

Refraction

The bending of light as it passes between two mediums with different optical densities.

Optical Density

A measure of how well a medium can transmit light.

Specular Reflection

Reflection that occurs on smooth surfaces, resulting in clear images.

Diffuse Reflection

Reflection that occurs on rough surfaces, scattering light in many directions.

Law of Reflection

The angle of incidence is equal to the angle of reflection.

Index of Refraction

The ratio of the speed of light in a vacuum to the speed of light in the medium.

Snell's Law

Describes how light refracts when passing between different mediums.

Critical Angle

The smallest angle of incidence for which light is completely reflected within a denser medium.

Total Internal Reflection

Occurs when the angle of incidence exceeds the critical angle.

Prisms

Optical devices used to separate white light into its spectrum and change its direction.

Convex Lens

Thicker in the center; focuses light to a point.

Concave Lens

Thinner in the center; spreads light out.

Additive Color Theory

Mixing colors through light; primary colors are red, green, and blue.

Subtractive Color Theory

Mixing colors through physical dyes; primary colors are cyan, magenta, and yellow.

Virtual Images

Images that cannot be projected; appear upright.

Real Images

Images that can be projected onto a screen; appear inverted.

Macula

The part of the retina responsible for detailed central vision.

Rods

Photoreceptors sensitive to low light and grayscale.

Cones

Photoreceptors that detect color and function well in bright light.

Cataracts

A condition where the inner lens of the eye becomes darkened or opaque.

Myopia

Nearsightedness; rays converge in front of the retina.

Hyperopia

Farsightedness; rays converge behind the retina.

Astigmatism

Irregularly shaped cornea that causes near and farsightedness.

Presbyopia

Aging process resulting in difficulty focusing on close objects due to lens hardening.

Polarization

Buzzword describing the orientation of light waves in specific directions.

Wavelength

The distance between successive crests of a wave, usually measured in meters.

Frequency

The number of waves that pass a fixed point in a unit of time, usually measured in Hertz (Hz).

Amplitude

The height of the wave from its rest position, related to the intensity of the light.

Spectroscopy

The study of the interaction between light and matter, often used to analyze the composition of substances.

Photoelectric Effect

The emission of electrons from a material when it absorbs light energy.

Chromatic Aberration

A distortion in color appearance in an optical system due to different wavelengths being refracted by different amounts.

Luminous Flux

The measure of the perceived power of light, measured in lumens.

Illuminance

The amount of light that falls on a surface, measured in lux.

Optical Fiber

A flexible, transparent medium used to transmit light signals over long distances.

Ultraviolet Light

Light with a wavelength shorter than visible light, often associated with effects like sunburn.

Infrared Light

Light with a wavelength longer than visible light, often felt as heat.

Laser

A device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.