PSYB51H3 Lecture Notes - Lecture 2: Photopic Vision, Optic Disc, The Blind Spot
Document Summary
Light: a wave; a stream of photons (tiny particles that each consist of one quantum of energy) Our visual system categorizes wavelengths into colours so we can better perceive and recognize: colours range from about 400 nm to 700 nm (blue to red) Consider light as a wave or as particles (photons) Light can be: absorbed: taken up, transformed to other forms of energy, transmitted: convey light from one place to another through transparent medium. Ex. fancy camera lenses; allows only red wavelengths to pass through it, which brightens red objects in pictures. Absorbs all other wavelengths which gets transformed into heat (think how black clothes are warmest: reflected: energy that is redirected when it strikes a surface. Mirror as the classic example: diffracted: bent, or having waves spread out. Ex. waves of sound or light as they encounter an obstacle (pass through a narrow aperture) Ex. when we see the rainbow, light is diffracted (spread out)
