- #1
newton1
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how many peak sensitivity of the human eye?
How many peak sensitivity of the human eye?
- Thread starter newton1
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- Eye Human Peak Sensitivity
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Discussion Overview
The discussion revolves around the peak sensitivity of the human eye, particularly focusing on the minimum light quanta required for detection and the efficiency of the eye in responding to light. It includes references to experimental findings and theoretical interpretations.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests that the human eye can detect as few as 15 quanta (photons) of light to elicit an action potential in ganglion cells.
- Another participant references an experiment indicating that the dark-adapted human eye could respond to just one quantum of radiation, questioning how this aligns with the previous claim.
- A different participant mentions the human eye's quantum efficiency being around <10%, suggesting it is better than photographic film but limited in its ability to integrate light.
- There is a suggestion that the human visual system may have some ability to integrate light, though it is unclear whether this occurs in the eye or the brain.
- Participants express amazement at the eye's ability to respond to a single photon of light.
Areas of Agreement / Disagreement
Participants express differing views on the minimum quanta required for detection, with some citing 15 quanta and others referencing the ability to respond to one quantum. The discussion remains unresolved regarding the definitions and interpretations of these findings.
Contextual Notes
There are potential limitations in the definitions of "respond" and the conditions under which sensitivity is measured, as well as the context of the experiments referenced.
- #2
SamLuc
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I'm not sure I understand te question, but, as far as I know, the human eye is sensitive enough to detect 15 quanta (photons) of light.
Is that the info you're looking for?
Is that the info you're looking for?
- #3
SamLuc
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That info is taken from 'Sensory Systems: Anatomy and Physiology' by Aage R. Moller. I presume it means that 15 quanta is the minimum required to elicit an action potential in a ganglion cell (these are the cells whose axons form the optic nerve).
Anyway, if this isn't the info you're looking for, http://webvision.med.utah.edu/facts.html page - which contains various facts and figures about the human retina - might help you. In fact, that entire site is a very good resource on vision; it might be worth bookmarking!
Anyway, if this isn't the info you're looking for, http://webvision.med.utah.edu/facts.html page - which contains various facts and figures about the human retina - might help you. In fact, that entire site is a very good resource on vision; it might be worth bookmarking!
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- #4
selfAdjoint
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There was an experiment decades ago that showed the dark adapted human eye could respond to just one quantum of radiation. I don't know how the textbook squares with that - might be two different definitions of "respond".
- #5
SamLuc
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Yeah, probably is! That's pretty amazing when you think about it, IMO - i.e. responding to a single photon of light!
- #6
Nereid
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IIRC, the human eye has a 'quantum efficiency' - which is pretty much the same as what SamLuc posted - of ~<10%, also in line with SamLuc's post.
Better than photographic film, but very limited ability to integrate (but apparently the human visual system does have some ability; am not sure if it's in the eye or the brain).
Then along came CCDs.
Better than photographic film, but very limited ability to integrate (but apparently the human visual system does have some ability; am not sure if it's in the eye or the brain).
Then along came CCDs.
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