yeah actually its probably right let me take some points from the lecturers notes
wavelength sensitivity:
in rods and cones the photopigment always consists of 11-cis-retinal combined to a protein opsin molecule. ALL rods have the same opsin molecule and the unit (opsin+11-cis-retinal) in rods is called rhodopsin. Cones have one of 3 different opsins and these opsins differ from that in rods. the opsin structure determine which wavelength of light the photopigment is most sensitive to. ALL rods have the same wavelength sensitivity curve. cones have 3 differnt curves depending on the opsin they have..... there is the short wavelgnth cone (blue light), medium wavelngth cone (green light) and a long wavelgnth cone (for red light) the rhodopsin has a optimal wavelngth of eh...i would say around 480-500nm can't tell precisely from the graph. ...
heres a graph of what im talking about!
http://mcdb.colorado.edu/courses/3280/images/photoreception/four-spectra.gifso yeah i think thats why i was confused cause there is a 'blue' cone so i thought it was the cone....eh
rods are more sensitive to light than cones because they contain more photopigment and the light activated cascade is more efficient in rods than cones. this means that rods are almost non-functional in the daylight.. cones are less affected because they have efficient light adaptation mechanism. therefore daylight viewing is better in cones than rods. night vision is dependant on rods. Rods respond slowly to and recover slowly to light stimulus. cones respond rapidly and recover rapidly, so rods are NOT good in detecting rapid changes in a stimulus but cones can.
ok...
cones are not DIRECTLY connected to retinal ganglion cells, they contact bipolar cells which contact RGC. two ways in which info. from cones can flow to RGC- direct pathway from receptors to bipolar cell to RGC and an indirect pathway where horizontal cells and amacrine cells are invovled....won't go into detail here...acuity comes from receptor field size and the amount of convergence.. acuity is highest at the fovea and descreases peripherally...
property foveal (cone) vision non foveal (rod) vision
directionality axial only any direction
wavelength sensitivity colour vision non colour vision
absolute sensitivity low sensitivity, day vision high sensitivity, night vision
type object detection detects rapidly detects slowly, detects only slowly
detects rapidly moving/changing objects moving/changing objects
acuity of vision high acuity, fine detail vision low acuity, detection vision