Colour Vision Flashcards
What is wavelength
The distance from one wave peak to the next
How do colors differ from one another
By their different wavelengths
What is the wavelength range that we can typically see
400nm (violet) to 700nm (red)
Why can we see these specific wavelength peaks from an evolutionary standpoint
Because the sun peaks there too and the earth’s atmosphere is transparent to these wavelengths
What wavelength is sea water most transparent at when eyes first evolved
Less than 500nm
What is the color cone percentage breakdown for human eyes
Red: 63%
Green: 31 %
Blue: 6%
Why are we called trichromatic
Because we see color with three types of cones
What wavelength color does rhodopsin prefer
Blue-green
What wavelength color does melanopsin prefer
Blue
What happens when your red cones are hyperpolarized? Why
When your red cones are hyperpolarized, your blue ones will not be and you will perceive yellow. This is because yellow light affects red and green cones
Primary colors
Red, blue, and green
Spectral colors
Colors that can be evoked by light of a single wavelength. Include rainbow colors
Extraspectral colors
Colors that are evoked from the 2 or more wavelengths mixed together.
Purple is an example because the wavelengths affect red and blue cones more than green ones
Fill in the blank.
Ganglion cell color signals are combinations of ________________.
Cone signals
R+G cells
Ganglion cells are excited by red and green light.
Aka yellow channel
R-G cells
Ganglion cells that are excited by red light and inhibited by green.
G-R cells
Ganglion cells inhibited by red light and excited by green light
What is the name of the R-G and G-R phenomenon
Red-green opponent channel
B-R-G
Cells excited by blue light and inhibited by red and green
blue-yellow opponent channel
B-R-G and B-R+G (blue minus yellow)
How can opponent channels explain afterimages
Your G-R cells (for example) fatigue and are less active, leaving R-G’s more active
What is the most common color-blind variant
Red-green colour blindness (daltonism)
Why are men affected more by colour blindness
Because the Red-Green variant lies in the X chromosome.
for females, if one X chromosome codes a fault pigment, the other X can compensate.
Reflectance
Surface’s tendency to reflect certain wavelengths of light and absorb others
