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Radio Waves. Cosmic Waves. 0. The electromagnetic spectrum can be represented as a sinewave. λ =10 6 meters. λ =10 -14 meters. Hue. 400 nm. 800 nm. λ. 1nm = one nanometer Equals 10 -9 meters (one billionth of a meter). Distance. Amplitude. Sinewave. Vitreous Humor. Acqueous
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Radio Waves Cosmic Waves 0 The electromagnetic spectrum can be represented as a sinewave λ=106 meters λ=10-14 meters Hue 400 nm 800 nm λ 1nm = one nanometer Equals 10-9 meters (one billionth of a meter) Distance Amplitude Sinewave
Vitreous Humor Acqueous Humor Fovea High Acuity Refraction = bending of light rays Sclera Cornea Pupil Optic Disk Convex Lens Retina (Accommodation)
Transduction Cone Photopigments: 700 nm 540 nm 480 nm Photoreceptors: Rods & Cones Rods contain rhodopsin or “visual purple”
What structure in your retina is responsible for highly detailed vision? • Optic disk • Rhodopsin • Fovea • All of the above
How well do you understand human vision, so far? • Extremely well • Almost there • So-so • Not very well • Help... I’m totally lost!
Thomas Young (1807)Hermann Van Helmholtz (1857) Trichromatic Theory: each cone cell contains one type of photopigment: 700 nm 540 nm 480 nm True at the level of the photoreceptors in the retina!!!
Ewald Herring (1878) Opponent-process theory: three antagonistically organized systems Red – Green Blue – Yellow Black – White Here, yellow is also considered to be a primary color True at the level of the optic nerve & thalamus!!!
Opponent-process theory Want proof? First, here is a definition of adaptation: A change in sensitivity following prolonged stimulation.
Which of the following color pairings is CORRECT? • green - yellow • blue - yellow • red - blue • all of the above