Some of the parameters of the human visual system are:
- 120 million rod cells in each eye
- 6 million cone cells in each eye
- 2000 cone cells in each fovea in the region of maximum uniform density
- 1 million nerve fibers in the optic nerve exiting each eye
- 250 million receptor cells in the two eyes versus 250 000 elements in a TV picture
- Distance from effective center of lens to fovea: 17mm
- Interpupillary distance: 50 to 70mm
- Visual angle subtended by fovea: 20 min of arc for region uniform max. cone density , 1-2 deg for rod-free area
- Angle with respect to visual axis of eye at which rod density is maximum: 15 to 20 degrees
- Rod cells are about 500 times more sensitive to light than cone cells
- Wavelength of visible part of electromagnetic spectrum : 0.4 to 0.7 micrometers
- Wavelength of maximum rod sensitivity: 0.51 micrometers (green)
- Wavelength of maximum cone sensitivity: 0.56 micrometers (orange)
- Intensity range : 10 exp 16 (160 decibels)
- Minimum visual angle at which points can be separately resolved: 10 to 60 seconds for dots
- Object distance from eye for stereoscopic depth perception: 10 in to 1500 ft
- Involuntary eye movements: 10 to 15 seconds of arc for tremor, slow drift of up to 5 min of arc
- Wavelength of maximum cone sensitivity: 0.56 micrometers (orange)
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