13.) Physiology of visual perception. Light perception. Adaptation Flashcards
what is visual perception ?
the ability to see items in the environment by light in the visual spectrum reflected off of it
what is the visible spectrum of light ?
390-700nm
visual preception is going through which mechanism ?
visual system starting of the retina ending in the visual cortex
the retina acts as a ?
transducer - where light from the environment is converted to a neuronal impulses
based on feedback from the visual system what changes?
the lens changes it;s thickness to the focus the light on the photoreceptive cells of the retina
the retinal contain three different cellular levels which are ?
photreceptor layer
bipolar layer
ganglion layer
what are cones responsible for ?
colour reception
red , green , blue
what are rods rposible for ?
view objects in low stimulation
photoreceptors contain a special photopigment called ?
opsin - protein
11-cis-retinal lipid - derivative of vitamin a
3 different types of photopigmnet present res[onding to specific wavelength of light
what happens when the specific range of wavelength of light hits that specific photopigment ?
the photopigment splits into two - sending a message to the bipolar cell layer - sending a message into the ganglion cells - then into optic nerve
converts the 11-cis retinal to all trans retinal
if there is not the appropriate photopigment in the photoreceptors what does this result in ?
colour vision deficiency
trichromacy , bichromacy , monochromacy , achromacy
rod vision detects what really well other than colour?
edges and motion
what is the photochemical substance in rods ?
rhodopsin
where does the cones have the highest concentration ?
in fovea
what is the photochemical substance in the cones ?
iodopsin
