What is the difference between rod and cone?

So on the foundation of colour vision, cones are of three types; red, blue and green, cones are less sensitive to light. The rods are most sensitive to light and dark changes, shape and movement and contain only 1 type of light-sensitive pigment. In a dim room, however, we use mainly our rods, but we have been “color blind.” Rods are more numerous than cones in the periphery of the retina. Next time you intend to visit a dim star during the night, try to look at it with your peripheral vision and use your ROD VISION to see the dim star. There are about 120 million rods in the human retina.

Although cones commence to contribute to visual perception at concerning the degree of starlight, spatial discrimination continues to be very poor. Mesopic vision occurs in levels of light of which both rods and cones contribute—at twilight, for instance.

Key Differences Between Rods And Cones

420 nm, 534 nm, and 563 nm and the sensitivity may raise to provide vision on the visible spectrum. Deficiency of cones can lead to the colourblindness in humans, and the person will be unable to distinguish among various colours. In eye, three distinct forms of cone cells are present based on their pattern of reaction to direct wavelength of light. Cone cells are somehow shorter than rods, but wider and tapered and are much less numerous than rods in most part of the retina, but greatly outnumber rods in the fovea. Just like rods, every cone has a synaptic terminal, an inner segment and an outer segment as well as an interior nucleus and different mitochondria. The chemical changes that occur when light strikes the cones are ultimately relayed as impulses to optic-nerve fibres that enter the mind.

One the main retina does NOT contain any photoreceptors. That is our “blind spot.” Therefore any image that falls on this region will never be seen. It is in this area that the optic nerves get together and exit the eye on their way to the brain. Since the cone takes a advanced of light to be able to send signals, the cones are primarily in charge of your visual acuity .


Cones are a type of photoreceptors in the retina, which are responsible for the colour vision at daylight. About 6 million cones can be identified in the retina. The vision of cones is gained under high light conditions. The sort of vision gained by cones is named photopic vision. Fovea centralis includes very thin, densely-packed cones. There are 6 million to 7 million cones in the average human retina.
The photopigments transform the light stimuli into electrical impulses. Rods have more outer segment disks in the long outer segment and subsequently contain more photopigments.

  • cells are the two types of photoreceptor cells found in the retina of eyes.
  • There are nearly 7 million cones that appear cone-like .
  • This difference in adaptation is apparent in the time span of the response of rods and cones to light flashes.

is obvious. The thing is primarily the poor resolution of the rod system .
Rather, the change in current produced by single photon capture in cones is comparatively small and difficult to tell apart from noise. Another difference is that the response of an individual cone will not saturate at high levels of steady illumination, as does the rod response. Although both rods and cones adjust to operate over a range of luminance values, the adaptation mechanisms of the cones tend to be more effective.

The sort of vision gained by cones is referred to as photopic vision. Eye contain receptors called photoreceptors viz rods and cone cells, which convert the energy of specific wavelength into action potential of nerve fibre. The retina has about 6 million cones and 120 million rods. Rods and Cones are the photoreceptors, useful in providing vision to the eyes. Rods provide vision during dim light or night also referred to as scotopic vision, whereas cones provide vision during day time or at bright light also referred to as photopic vision. The real work in the retina is performed by light-sensitive cells known as photoreceptors.

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