Spectral sensitivity of the human eye
From WikiLectures
Spectral sensitivity is the relative efficiency of detection of light or other signal, as a function of the frequency or wavelength of the signal.
There are two basic types of retinal photo-receptors
- Cones cell -> responding to bright-light condition (Photopic vision). And these cells concentrated in the center of the retina.
- Rod cell -> responding to low-intensity light condition (Scotopic vision).
Depending on their spectral sensitivity, belong to
- Long-wavelengths sensitive (L)
- Mid-wavelengths sensitive (M)
- Short-wavelengths sensitive (S)
Spectral sensitivity of eye is influenced by light intensity.
Light intensity determines...
- The level of activity of cones & rods.
- Main characteristic of human vision
Visible spectrum
- visible spectrum means sensitivity of cones & rods. It varies with the wavelength.
- Wavelength ranges between 380 nm and 800 nm.
Sensitivity of human eye
- Sensitivity of human eyes to light increase with the decrease in light intensity.
- In day-light condition, the eye is most sensitive at 555 nm.
- In darkness condition, the eye is most sensitive at 507 nm.
Conclusion
- As light intensity decreases, cone function changes more effective way.
- When decrease the light intensity, it prompt to accumulation of rhodopsin. Furthermore, in activates rods, it allows to respond to stimuli of light in much lower intensity.
Source : Gigahertz-optic : http://www.light-measurement.com/spectral-sensitivity-of-eye/ Wikipedia : http://en.wikipedia.org/wiki/Spectral_sensitivity Naver : http://endic.naver.com/enkrEntry.nhn?entryId=59b4cdfcbb25434ba38c5c79f0d3c82f Naver : http://terms.naver.com/search.nhn?query=spectral+sensitivity&where=&x=0&y=0
