Quiz 1 Flashcards
Sensation
Activation of our 5 senses
Perception
The putting together of information that we have in the physical world
Computer vision
Computers take a really long time to learn
Top down processing
Knowledge based (I know what a cat is)
Bottom up processing
Data based / stimulus based (Is it soft? Does it have a tail?)
Distal stimulus
Constant properties, 3D, real life object
Proximal stimulus
Varying properties in size and shape, 2D, also flipped upside down
Perception stimulus
Constant properties, what we see, 3D
What light is visible to us?
400-700nm
What are the 2 parameters of light?
Wavelength and intensity
Cornea
bends light to point on retina (fixed focal lens that bends light the same amount)
Lens
changes thickness and curvature based on distance
Acommodation
Lens is thinner, less curved when looking far away. Lens is thicker, more curved when looking close.
Myopia
Nearsightedness
Difficulty in focusing distant points
Hyperopia
Difficulty in focusing at close distances
Presbyopia (“old eye”)
Failure to accommodate, near point changes
What are the eye diseases of the cornea?
Myopia and hyperopia, due to curvature of cornea
Astigmatism (main)
Aqueous Humor
Clear substance between cornea and lens that provides nutrition and cushioning
Pressure, nutrients, clear debris, every four hours
What is the disease involving the aqueous humor?
Glaucoma
Pressure in eye due to aqueous humor not draining correctly
Iris
Muscle surrounding pupil
Pupil
A gap that allows light into the eye
Main disease caused by lens problems?
Cataracts: opacities in the lens
Vitreous Humor
Provides nutrition and support to the eye
DOES NOT FLUSH
Fovea
Center of retina that helps with detailed vision
Photoreceptors
On the retina and contain photopigments that are sensitive to light
Rods
120 million in each eye
Very sensitive to light
500 x more sensitive than cones
No cells in fovea
High concentration in periphery
No color
Cones
Daytime system
6 million in each eye
Fovea only has cones but most are outside the fovea
Color vision
Optic Disk
Region where optic nerve fibers exit the retina
Blindspot; no receptors
Dark adaptation
Increase in sensitivity to light that takes place as the eyes stay in the dark
Photopic
day or well lit environment
Mesopic
Dusk or dawn
Scotopic
Night or dark
Purkinje shift
Increased sensitivity to short wavelengths when switching from cones to rods
Visual Acuity
At birth, vision is 20/500
Rapidly increases to 20/40 by 6 or 7 months old
