PSYB51H3 Chapter 2: Chapter 2 Notes
Document Summary
Chapter 2: the first steps in vision: seeing stars. Light is a small part of electromagnetic spectrum: visible light is between 400-700 nm, red (long) waves are 650nm, violet (short) waves are 400nm. Light can be: absorbed: take up energy, but doesn"t pass o. gives dark surface appearance: scattered: disperse in weird pattern, reflected: redirect energy from surface. gives light surface appearance: t ransmitted: transfer w/o absorbing or reflecting, refracted: course of energy is changed as it passes from something to another medium. Shining starlight onto the retina: cornea is most refractive, to focus light, accommodation: change in focus. Changes refraction by changing shape: does this by changing ciliary muscle, far objects: culinary muscles relaxed, zonules stretched, lens is flat, close objects: culinary muscles contracts, zonules relaxed, lens bulges. muscle has opposite effect on zonule: fatter lens is more powerful. Lens can vary up to 15 diopeters: age, presbyopia: old sight.
