are rods and cones the human eye's feature detectors?
535997
no, feature detection is done by other cells, e.g. center surround detection in retinal ganglion cells, but also by cells in the visual cortex of the brain. \nWhere and how depends on what feature you are talking about.
477648
http://www.seeingwithsound.com/etumble.htm\nhttp://www.howstuffworks.com/artificial-vision.htm\nhttp://www.wired.com/wired/archive/10.09/vision.html
546982
Their function is essentially the same.  Like cameras, eyes have a lens that helps focus the image and a receptor of the image, called film in cameras, we have a retina filled with nerve endings that detect light sends it over to our brain to get interpreted.
883235
If you are looking into someones' eye thrugh an opthmaloscope you see through the cornea, through the pupil and lens, through the vitreous gel and see the retina. You can see the capilaries and bleeding and scarring . you can see where the optic nerve leaves.You can detect cataracts.\nYou do not see individual rods and cones,
43367
Each of the eyes are slightly recessed, and each eye points in a slightly different direction.  This makes it so that depending on which eye detects the most light, the insect is able to determine the direction of the light.  Humans, by contrast, find the location of light by having a lens which focuses the incoming light on the photo-sensitive retina at the back of the eye.
64730
That really is a fun and interesting question!!!\n\nOur cones are not necessarily identical, which means that out perceptible gamut will not map identically on the xy plane. (Click on the link from Discover Labs listed below for pictorial examples of these differences, for example in color blindness) \n\nHowever the difference for most of us is so insignificant that it doesn't matter. \n\nThat is what professionals like photographers, artists and cinematographers, etc. base their success in their professions on. Also remember that colors are not arbitrary but are determined by their wavelengths. There may be some other issues on a quantum level, More...\n\nYou'll find some fun, interesting and easy to understand theory in addition to great explanatory  illustrations here at this link:\n\nhttp://www.discover.uottawa.ca/~aelsawah/csi4133/Lab02.htm
448426
We are able to see things even when not looking at them directly. It is 180 degrees for men and 360 degrees for women.  Therefore, we can 'sense' it when someone is training their eyes on us.
796290
A person suffering from night blindness cannot produce any 'visual purple' in his rods which are on his retina. Rods are used to see in dim light while cones are used to see colours vividly in bright light. Since his rods do not function properly, the person will not be able to see in dim light. e.g. when he is driving at night on a road with no street lights. However he will be able to see under bright light at night.
607436
This question is a topic of current research—several groups are measuring how fine a difference between two colors can be perceived. This type of measurement will ultimately help us determine how many colors the "average" human can perceive. The research is part of a larger field called psychophysics.\n\nColors are first detected by individual cones in the retina. These cones contain various opsin pigments, which absorb only red, green, or blue light, depending on the pigment's absorption spectrum. The information about what colors have been absorbed is sent to the visual cerebral cortex of the brain. Quite a bit of integration and processing of this signal occurs before it reaches its ultimate destination.\n\nIt is now believed that humans can perceive on the order of millions of colors. Most estimates are around 10 million. This makes sense when we consider, for example, computer monitors: We notice a difference when we switch from "thousands" to "millions" of colors. Millions in this case corresponds to 224—or 16,777,216—colors for a 24-bit display. Of course, this simple test only tells us that we can see more than "thousands" of colors, but it doesn't give us an upper limit. According to Kandel et al. (reference below), "The superiority of color perception over brightness perception is evident in the fact that we can discriminate only 500 gradations of brightness but we can discriminate more than 7 million gradations of color."\n\nBecause people vary in the overall number of cones they have and the number of each cone type, they vary in the number of colors they perceive and in what color is perceived given a particular input color at the retina.
531806
The back of your eye is a multi-layered sheet of tissue called the Retina. The retina contains millions of special cells called photoreceptors. Photoreceptors contain a special molecule called Rhodopsin. Rhodopsin is broken by light into Opsin and Retinal, causing a chain of events resulting in a message to your nervous system. There are two major types of photoreceptors; rod cells and cone cells. The rhodopsin in Rod cells is most sensitive to low levels of (blue-green) light, and thus rod cells are responsible for your night vision. (notice that dark-red light doesn't leave an afterimage in the dark and destroy your night vision - it doesn't activate rod cells and use up their rhodopsin very much). Cone cells are responsible for color vision. Three types of cone cells exist, and each type contains modified rhodopsin that is most sensitive to red, blue or green light respectively. The information sent from the cone cells is sent to the fourth and third layers of the optic cortex in the back of your brain, where "Blob cells" are the first step towards integrating color information. A full-color picture is assembled from these seperately color-sensitive cells, just as the red-green-blue dots on a television screen merge into a full-color image. However, it is important to keep in mind that the separate photoreceptors are each sensitive to a RANGE of light-frequencies, of which red, blue and green are responded to best. \n     The retinas of color-blind animals do not contain all three cone cell types, if any at all. For this reason, animals rely more on motion than on fine detail to understand their visual environments. Humans can become colorblind as well, when mutations occur in any of the three varieties of rhodopsin used in cone cells. Some animals do have color vision (like birds) and others (like bees) can see light that we can't (i.e. ultraviolet). The necessary photoreceptor cells are found in the retinas of these animals.
94315
To Improve Peoples Eye Vision
982980
In the eye there r rods N cones. rods allow us to see details while cones colours! cats n dogs have more rods than human beings.
240084
They receive and react to the reception of stimuli. For example, rods and cone cells of the retina receive light, taste and smell receptors. The skin contains several types of receptor cells.\nThere are various types of receptor cells within the body too; proprioreceptors of the musculo-skeletal system, chemoreceptors involved in homeostsis, etc.\nOnce stimulated, receptor cells initiate an action potential in an associated sensory neurone.
700451
Different photoreceptors respond more or less strongly to different wavelengths (colours) of light. Digital cameras use more than one type of photodector for each pixel of the picture. By comparing the strengths of the signals from different detectors you can tell what colour the pixel should be.\n\nFilm cameras do the same thing, but use different chemicals in the film instead of photodectors. The different chemicals respond to different wavelengths of light.
56416
Fly eyes work like fantastic motion dectectors. Their sight system is completely different for a very different reason. Detecting motion not specific visual acuity
455075
The sensory receptors for the eye is the retina and optic nerve, specifically cones and rods in the retina, for the nose it is the olfactory nerves
819846
I am an MD. This is a very interesting question. The resolution of the naked eye among people with the finest vision is about 1 arc minute. Star discs are far, far, smaller than this, so how can the eye see something that is that small? The answer is that a typical star image, though exceedingly small, is nevertheless very bright when compared to the night sky. The star image will appear as a diffraction (Airy) disk on the surface of your retina that is about one arc minute in diameter that is too bright to be ignored. Your retinal cells process the incoming light and send the signal to your brain, and what you perceive is a tiny bright speck. This is perhaps equivalent to your digital camera showing a star image consisting of a single pixel being illuminated. I hope this helps.