Vision Flashcards
Three steps from stimulus to perception
Reception, transduction, coding
Light
Adequate stimulus for vision. Described as a particle of energy wave of energy (e-magnetic energy)
2 properties of light
- Wavelength = color
2. Intensity= brightness
Wavelengths of light (violet-Red) based on rainbow
400-700
Pupil
Where Light enters the eye.
Size changed in response to changes in illumination
Sensitivity
Ability to see when light is dim
Acuity
Ability to see details
Lens
Focuses light on the retina
Ciliary muscles
Alter the shape of the lens as needed
Accommodation
Process of adjusting the lens to bring the images into focus
Blind spot
No receptors where info exits the eye
Completion
Visual system uses info from cells around the blind spot to fill in blind spot (completion)
Fovea
High acuity area at center of retina
Thinning of ganglion cell layer…
Reduces distortion due to cells between The pupil and the retina
Duplicity theory of vision
Cones and rods mediate different kinds of vision
Cones
Photopic (daytime vision)
High acuity color info in good lighting
Only cones found in fovea
Rods
Scotopic (nighttime vision)
High sensitivity, allowing low acuity vision in dim light. Lack detail and color info.
More convergence. Increasing sensitivity while decreasing acuity.
Visual transduction (in light) step 1
Light bleached rhodopsin molecules