COGS 101A Lecture Notes - Lecture 4: Presbyopia, Far-Sightedness, Sclera
● Vision
○ Stimulus in environment > light is reflected and focused > sensory receptors
○ Electromagnetic spectrum
■ 10^-14 to 10^6 meters
■ In this class, light is a wave in environment and a particle when it is
interacting with neurons and sensory receptors
■ 400-700 nanometers
○ Vision and light
■ Absorbed
● Exp. if a wine glass were to be heated up then there would be
absorption
■ Transmission
● Light can be bent in a smooth way
● Dispersion
■ Reflected
● Bounces off and object
■ Color of an object depends on how it reacts with light
■ Light is reflected in multiple places of an object; but we only see one point
of the light reflected to get an image through a pinhole
● Larger the pinhole the fuzzier the image
○ Eye
■ Pupil > focused by cornea and lense > retina (where sensory receptors
are)
■ Retina
● Back of the eye
● Macula
○ Cone-rich area; fovea in the center of the macula
● Optic Disc
○ Where optic nerve leaves the eye
○ Blind spot, don’t notice it, it’s not in immacula (point of
focus), brain fills in missing info
■ Cornea; rigid, concentrates light
■ Pupil; lets light in, responds to light and emotional stimulus
● Pupillary light reflex
○ If one eyes reacts to light the other eyes will do the same
■ Lens; can change shape
● Ciliary muscles change the shape of the lens
● Far point, when your eye is relaxed and the lens is flat, makes a
crisp image
● Accomodation, changing the shape of the lens to form the crisp
image
● Near point, closest you can bring and object keep it in focus ( the
most ciliary muscles can constrict)
Document Summary
Stimulus in environment > light is reflected and focused > sensory receptors. In this class, light is a wave in environment and a particle when it is interacting with neurons and sensory receptors. Exp. if a wine glass were to be heated up then there would be absorption. Light can be bent in a smooth way. Color of an object depends on how it reacts with light. Light is reflected in multiple places of an object; but we only see one point of the light reflected to get an image through a pinhole. Larger the pinhole the fuzzier the image. Pupil > focused by cornea and lense > retina (where sensory receptors are) Cone-rich area; fovea in the center of the macula. Blind spot, don"t notice it, it"s not in immacula (point of focus), brain fills in missing info. Pupil; lets light in, responds to light and emotional stimulus.
