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Sticks and cones


Where is the difference?


On the retina of the eye there are two different types of sensory cells that respond to different wavelengths of light.
So-called Stдbchen allow seeing at dusk / night, which is also known under the concept of scotopic vision (Greek skotos = darkness). These sensory cells have a special sensitivity to light and, even with a small amount of light (for example, weak moonlight), can generate useful pulses for the brain.
The other receptor type is responsible for daytime vision and also has its own technical term with photopic vision (Greek: photos = light). In daylight, the so-called react spigot, Here you can distinguish between three different types of pins: S-peg (reacting to blue), M-peg (reacting to green) and L-peg (reacting to red). The abbreviations stand for the respective wavelength range to which the individual pin types react (short, medium and long).

Table: Comparison of sticks and cones

Stдbchenspigot
Engl. termrod cellscone cells
OccurrenceRetinaRetina
highest densityin the periphery (around the Sehgrube)in the fovea centralis (Sehgrube)
number100-125 million5-7 million
shapelдnglichin comparison with sticks shorter
functionscotopic vision (seeing at dusk and darkness)photopic vision (color vision or vision during the day)
receptor typesonly one type of receptorBlue receptors, green receptors, red receptors
highest photosensitivityabout 500nmBlue receptors (about 420nm), green receptors (about 530nm), red receptors (about 560nm)
Opsin (visual pigment)Skotopsins (rhodopsin only)Photopsins (three iodopsines)
sensitivityhigh (a light photon is sufficient for a reaction)low (over 100 light photons are needed for a reaction)