Vision Flashcards
Where does the first stages of visual processing occur?
Retina
What is retinal projection?
Small, inverted 2D image distorted by the curvature of the eye
What are specialised for day vision?
Cone cells
What are specialised for night vision?
Rod cells
What is opsin?
Light sensitive protein in membrane go photoreceptors
What is opsin needed for?
Transduction
What are the 3 classes of cone cells?
S-, M- and L-
How do the types of cones differ?
Differ in wavelength affinity to absorb light
How many functional classes of rod cells are there?
1 - express the same type of opsin (rhodopsin)
What are the first steps in processing an image?
- Lens focuses image
- Aperture to control light entering the iris
- Pixels register image (Photoreceptors)
- Filtering media
- Lens cover (eye lid)
- Cleaning mechanism (tears)
What is visual acuity?
Ability to solve spatial details
Where is acuity highest?
Fovea
What is the pathway of serial connections in the retina?
Photoreceptors -> Bipolar cells -> ganglion cells -> thalamus and the brain areas
How are horizontal cells involved?
Receive input from photoreceptors and project to bipolar cells
How are amacrine cells involved?
Receives input from bipolar cells and project to ganglion cells