The Retina

The retina is the back part of the eye that consists of the cells thatrespond come light. These committed cells are called photoreceptors. There space 2 varieties of photoreceptors in theretina: rods and cones.

You are watching: Which process allows more light to reach the periphery of the retina

The rods are most sensitive to light and also dark changes, form andmovement and contain only one form of light-sensitive pigment. Rods arenot great for shade vision. In a dim room, however, us use largely ourrods, however we room "color blind." Rods are more numerous 보다 cones in theperiphery the the retina. Next time you want to check out a dim star in ~ night,try come look in ~ it v your peripheral vision and also use your ROD VISION tosee the dim star. Over there are around 120 million rods in the humanretina.

The cones are not together sensitive come light as the rods. However, hat aremost perceptible to one of three different colors (green, red or blue).Signals indigenous the cones are sent out to the brain which then translates thesemessages right into the late of color. Cones, however, occupational only inbright light. That"s why friend cannot see color an extremely well in dark places. So, the hat are used for shade vision and also are far better suited fordetecting well details. Over there are about 6 million cap in the humanretina.
Some people cannot tell some colors from rather - thesepeople are "color blind." Someone who is shade blind go not have actually aparticular type of cone in the retina or one type of cone might be weak. In the general population, around 8% of every males are shade blind and also about0.5% of every females are color blind.

The fovea, shown here ~ above the left, is thecentral an ar of the retina that gives for the most clear vision. Inthe fovea, there are NO rods...only cones. The cones are additionally packedcloser together here in the fovea 보다 in the rest of the retina. Also,blood vessels and nerve yarn go around the fovea so light has actually a directpath to the photoreceptors.

here is one easy way to show the sensitivity of your foveal vision. Rigid at the "g" in words "light" in middle of the complying with sentence:

"Your vision is ideal when light falls on the fovea."

The "g" in "light" will be clear, however words and letters on either sideof the "g" will not it is in clear.

One part of the retina does not contain any type of photoreceptors. This isour "blind spot." Therefore any kind of image that drops on thisregion will NOT it is in seen. It is in this region that the optic nerves cometogether and also exit the eye top top their means to the brain.

To uncover your remote spot, look in ~ the image listed below or draw it ona piece of paper:


Close your left eye.

Hold the photo (or location your head native the computer monitor) around 20inches away. Through your right eye, look in ~ the dot. Slowly bring theimage (or relocate your head) closer if looking in ~ the dot. In ~ a certaindistance, the + will certainly disappear native sight...this is as soon as the + drops onthe remote spot of your retina. Turning back the process. Close your best eyeand look at the + through your left eye. Relocate the image slowly closer come youand the dot need to disappear.

Here is one more image that will assist you find your remote spot.


Forthis image, near your appropriate eye. V your left eye, look at the redcircle. Gradually move your head closer come the image. In ~ a certaindistance, the blue line will not look broken!

Did friend know?movie Why can"t friend see really well when youfirst enter a darkened room favor a movie theater? once you very first enterthe movie theater, the cones in her retina are working and also the rods arenot however activated. Cones need a lot of light to work properly; rods needless light to work, however they need around 7-10 minute to take over for thecones. After 7-10 minute in the dark, the rods perform work, however you cannotsee colors really well due to the fact that the rods carry out not provide any colorinformation. The cones, which do administer color information, need morelight, but do not work-related well in the dark. ~ the movie is over and also youleave the theater, everything looks very bright and also it is difficult to see fora minute or two. This is due to the fact that the rods become "saturated" and also stopworking in these bright conditions. That takes a couple of minutes for the conesto begin to function again, and also for typical vision to it is in restored.

Acomplete lesson arrangement on the eye and also itsconnections - teacher and student travel guide available. Also, try some experiments to test your sense of sight and take a short, interaction quiz about the eyeand sight.

See more: Los Angeles To Las Vegas Distance Between La And Las Vegas From Los Angeles

Find out more about remote spots, vision, the retina and photoreceptors.

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