Vision Study Guide Flashcards
What are the qualities of light?
-a form of electromagnetic radiation
(energy produced by vibrations of electrical light)
-measured according to wavelength
-can be reflected (visible), absorbed, or refracted (bent)
What do opsins absorb?
Photons
-tiny particles that each consist of one quantum of energy
What are the parts of the eye?
-Cornea
-Aqueous humor
-Iris and pupil
-Lens
-Vitrous humor
-Retina
Cornea
§ External structure of the eye
§No blood vessels or blood but lots of sensory nerve endings
Function: Thin transparent protective layer of your eye
Aqueous Humor
§ Under the cornea
§ Fluid filled chamber derived from blood (no red blood cells but a fluid filtered from blood)
Transparent
Function: supplies oxygen and nutrients while removing waste from the cornea and lens
Pupil
= the hole (black portion) in the muscular iris
Function: can expand and constrict
Iris
§ Colored portion of the eye
Function: Regulates the size of the pupil
(modifying the amount of light that enters the eye)
Lens
Function: refracts and focuses light
-accommodation
Vitrous humor
§ Fluid-filled chamber, gel-like, and viscous and is generally transparent in posterior eye
§ Experience Floaters
Function: accommodate light to hit the back of the retina
Retina
Function: transduce light energy into a neural signal by photoreceptors
Components of a photoreceptor
Function: detect visual information
-Rods
-Cones
Inner & Outer segment
Function of Inner segment of photoreceptors
produces:
visual pigments
neurotransmitters
proteins
and other cellular machinery
Function of outer segment of Photoreceptors
-stores visual pigments (opsin and chromophore)
Rods
= amount of light
-shapes and contrast of objects
-specialized for low light situations
-respond to scotopic conditions
-heavily relief on by nocturnal animals
Cones
= detect color; color vision
-respond to photopic conditions
-3 types of opsin +other colors appear via activation of multiple cones at once
What are the 3 types of Opsin in Cones?
S-cones
M-cones
L-cones
Opsin
=protein that determines what wavelength the photopigment transduces
What are the names of the different Opsins?
○ Rhodopsin
○ Photopsins
S-cones: color, size of wavelength, and distribution
-Blue
-Short
-highest density in Peripheral Retina
M-cones: color, size of wavelength, and distribution
-Green
-Medium
-highest density in Fovea
L-cones: color, size of wavelength, and distribution
-Red
-Long
-highest density in Fovea