PS261 Chapter Notes - Chapter 3: Retinitis Pigmentosa, Macular Degeneration, Keratomileusis
Document Summary
Vision is based on visible light, which is a band of energy within the electromagnetic spectrum: a continuum of electromagnetic energy that is produced by electric charges is radiated as waves. Wavelength: the distance between the peaks of the electromagnetic waves. Visible light: the energy within the electromagnetic spectrum that humans can perceive, has wavelengths ranging from 400-700 nm, where 1 nanometer. Light is reflected from objects in the environment and enters the eye through the pupil and is focused by the cornea and lens to form sharp images of the objects on the retina, which contains receptors for vision. Two types of receptors: rods and cones, that contain light-sensitive chemicals called visual pigments that react to light and trigger electrical signals. The signals then emerge from the back of the eye in the optic nerve, which conducts signals toward the brain.
