What color is best for the eye's resolving power?

In summary, the conversation discusses the resolution and perception of color in the human eye. It is noted that the eye does not have a resolution like a camera and the concept of "best for resolving power" is questioned. The number and distribution of color cones in the eye are mentioned, with some links provided for further information. It is also mentioned that the eye is most sensitive to a certain shade of yellow, corresponding to the wavelength of the sun's output. The effects of the Earth's atmosphere and evolution on the eye's sensitivity to light are also discussed. The conversation ends with a discussion on the sun's radiation spectrum and its potential effects on light and color perception. Overall, there is a focus on the functionality and evolution of the eye in relation
  • #1
alex_boothby
36
0
hi, i was just wandering what colour you see best in a why?, i mean if a room was to be flooded in red blue or green what would be the best for the resolving power of the eye.

thank you very much, alex
 
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  • #2
Your eye isn't like a camera; it doesn't have a resolution. What do you mean by "best for the resolving power?"
 
  • #3
i think he's just asking which one we see with most clarity. I think it depends more on the contrast with the colors around it than the individual color
 
  • #4
If I remember correctly the eye has different number of each color of cones that allow it to percieve color. About 2/3 of the cones percieve the color red. About 1/3 are for green and the 3 or 4% that I rounded off are meant to see the color blue.

I seem to remember reading some observations that all of the colors are perceived equally well in a normal eye. There was some speculation that some enhancement within the brain allowed blue to be seen as well as red. Whether the number of cones might have something to do with what color a person sees best, I have no idea.

Here are a few neat links with some information that might be useful to you.
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html
http://www.sciencedaily.com/releases/2005/10/051026082313.htm
 
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  • #5
The eye will react most sensitively to a certain yellow, corresponding to the wavelength that the sun outputs more then any others.

You can see what I am talking about by playing with this applet, although it doesn't have the sun as an example, but the 5000k is close:

http://webphysics.davidson.edu/alumni/MiLee/java/bb_mjl.htm
 
  • #6
Crosson said:
The eye will react most sensitively to a certain yellow, corresponding to the wavelength that the sun outputs more then any others.

Because the sun produces most output at a given wavelength, why does it follow that the eye "will" react most at that wavelength?

Filtering by the Earth's atmosphere has a large effect. The radiation power spectrum in low light conditions (cloudy skies, dawn and dusk, moonlight) is very different from the sun's black body spectrum.

The eye did not evolve for the purpose of looking at the sun. In fact humans have a strong reflex action to avoid looking directly at the sun, except when it is near the horizon and not very bright.
 
  • #7
The peak sensitivities don't occur at true, blue, green, and red. Here's a link to an article that shows the colors for the peak sensitivities for each color.

http://en.wikipedia.org/wiki/Color_vision
 
  • #8
I am pretty sure that the eye is most sensitive to green.
 
  • #9
The peak of sensitivity of the "normal" eye in normal illumination (not in low level illumination) is for 550 nm (bright green).
Look for the CIE curve.

The cones are not sensitive enough at low levels of light. In the dark only the rods are sensible enough. In low light you do not perceive colors. Rods are far more numerous than cones.
See this site:
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html

Of course the eye, as a camera, has a resolution. It is given by the aperture of the iris and the focal length. It corresponds fairly well to the distance between rods in the retina. It is supposed to be one minute of arc. That is you are supposed to resolve one thirtieth of the diameter of the moon.
 
  • #10
AlephZero said:
Because the sun produces most output at a given wavelength, why does it follow that the eye "will" react most at that wavelength?

Filtering by the Earth's atmosphere has a large effect. The radiation power spectrum in low light conditions (cloudy skies, dawn and dusk, moonlight) is very different from the sun's black body spectrum.

The eye did not evolve for the purpose of looking at the sun. In fact humans have a strong reflex action to avoid looking directly at the sun, except when it is near the horizon and not very bright.
Presumably, the eye would evolve to be most sensitive to the wavelengths most prevalent in one's surroundings, which would presumably be the precisely those wavelengths the sun emits in greatest abundance.
 
  • #11
Most of the light emitted by the Sun is in the infrared. But only a few species are sensible to these wavelengths.
One possible explanation is that eyes developed in water and in water there is not infrared. And we inherited the eyes of mollusks and fishes.
 
  • #12
lpfr said:
Most of the light emitted by the Sun is in the infrared.
Yes, but the infrared is a much wider range of frequencies than the visible spectrum, so that's a really poor comparison. Assuming things scale proportionally, it would take about 40 different kinds of cones to see in the infrared to the same amount of precision as we can see in the visible spectrum.

Put differently, if an organism could only see as much of infrared wavelengths as we can see in the visible wavelength, there would be much less light available to said organism.


NASA's site gives another useful bit of information:
http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html

The picture at the bottom suggests that, if I understand it properly, in addition to the blackbody effects we're discussing, that radio and visible light is essentially all of the sunlight that penetrates the atmosphere.
 
  • #13
Radiation coming from the Sun is almost identical to the radiation of a black body at the temperature of the Sun. The atmosphere filters more or less some bands, but is not very important. Unless of course if you want to use the absorbed light.
Infrared spectrum is, as Hurkyl wrote far larger than the visible one. But the energy density per hertz (or per nm) if also bigger. If nature have decided that our visible band was the infrared, it would not have been forced to make us see all of what we name IR spectrum It could have decided that we should see say between 800 nm and 1600 nm. In this case just the almost same three different color captors would have sufficed.
Anyway what is really important is the light and not the color. Color is just a complement. It helps to choose ripe fruits. But to escape to a predator it is the sensitivity in the night which is vital. Nature could have chosen another band of frequencies.
 
  • #14
Hurkyl said:
Presumably, the eye would evolve to be most sensitive to the wavelengths most prevalent in one's surroundings, which would presumably be the precisely those wavelengths the sun emits in greatest abundance.
(When you presume you make a pres out of u and me.) There's plenty of data that shows otherwise.
 

1. What is eye resolution and how is it measured?

Eye resolution refers to the ability of the eye to distinguish and perceive fine details or the sharpness of vision. It is measured in terms of visual acuity, which is the smallest detail that can be seen clearly. This is usually measured using a Snellen chart or the standard eye chart.

2. What is the difference between visual acuity and pixel resolution?

Visual acuity is a measure of the eye's ability to perceive fine details, while pixel resolution refers to the number of pixels per inch or centimeter in a digital display. Visual acuity is a measure of the eye's resolution, while pixel resolution is a measure of the display's resolution.

3. How does the eye perceive color?

The eye perceives color through specialized cells called cones, located in the retina. These cones are sensitive to different wavelengths of light and send signals to the brain, which then interprets them as colors. There are three types of cones: red, green, and blue, which allow us to see a wide range of colors.

4. Can the resolution of the eye be improved?

Yes, the resolution of the eye can be improved through corrective lenses, such as glasses or contact lenses, or through surgery. These methods can help to correct vision problems like nearsightedness, farsightedness, and astigmatism, which can improve the eye's overall resolution.

5. How does age affect eye resolution and color perception?

As we age, the eye's resolution can decrease due to changes in the lens and other structures. This can result in conditions like presbyopia, where the eye has difficulty focusing on close objects. Color perception may also change with age, as the number of cones in the eye may decrease, leading to a reduced ability to perceive certain colors.

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