Neurons of retina
- Cones and rods ○ Cones for colour, central
- ○ Rods, Black and white (grey scale), peripheral
- Bipolar cells
- Ganglion cells
- Cells in corpus, geniculate cells
Macula
- Has cones for colour
Cones
- In “high light”, they work better in more light
Rods
- Rods work better in lower light
- Rods pigment is called rhodopsin
Waves that cause defects
- UV waves + eyes ® Destroy layers of the cornea
- Infrared radiation ® Retina affected
Cone complement theory (pigments)
- Erythrolabe RED
- Chlorolabe GREEN
- Cyanolabe VIOLET
Young Helmholtz theory of colour vision
- Trichromacy ○ Presence of all red, green and violet pigments
- ○ Normal colour vision
Waves that cause defects
- UV waves + eyes ® Destroy layers of the cornea
- Infrared radiation ® Retina affected
Anomalous trichromacy (cannot see colours correctly or properly)
- Protanomaly
- Deuteranomaly
- Tritanomaly
degrees of anomalous trichromacy
- A,B,C ○ A is the worst
Colour blindness
- Protanopia RED colour blindness
- Deuteranopia GREEN colour blindness
- Tritanopia VIOLET colour blindness
Rockshi
Dichromacy
- can see 2/3 colours
Full blindness to 3 colours
- Achromacy is colour destruction e.g. macular degeneration
- Monochromacy, colour function of cones destroyed
Pseudo (iso) chromacy
- Patient shown 2 scales
- One with yellow and the scale is rotated with another scale with a different colour, they see colour change