myERCO

myERCO

Your free myERCO account allows you to mark items, create product lists for your projects and request quotes. You also have continuous access to all ERCO media in the download area.

Login

You have collected articles in your watchlist

Technical environment

Technical environment

Global standard 220V-240V/50Hz-60Hz
Standard for USA/Canada 120V/60Hz, 277V/60Hz
  • 中文

Our contents are shown to you in English. Product data is displayed for a technical region using 220V-240V/50Hz-60Hz.

{{ tu_banner_headline }}

tu_banner_copy

Rods (eye): specialised cells for light-dark vision

Rods (eye): Illustration depicts the location of the receptor cells.

Rods belong to the sensory cells in the eye and enable us to see light and dark: Because of their high sensitivity to light, we can still see with them at dusk or under a bright full moon.

Would you like to find out more?

What is the function of the rods in the eye?

Rods belong to the photoreceptors and are sensory cells for the visual perception of light. The retina has about 120 million rods. The highest density of rods is in a ring-shaped zone around the fovea centralis, the area of sharpest vision. The fovea centralis itself has no rods.

The rods in the eye are used to perceive light and dark and can also register very weak light pulses. With increasing twilight (mesopic vision) and at night (scotopic vision), the eye changes from cone vision (photopic vision, day vision) to rod vision. Unlike cones, no colour vision is possible with rods.

Proper fixation on objects through rod vision is not achieved: high visual acuity is only present in the area of the fovea centralis. The cones, that enable sharp vision, are concentrated in this fovea (area of sharpest vision). The rods, on the other hand, are distributed over the entire surface of the retina. This means there is a greater ability to perceive movement in the entire field of vision. We thus see even the slightest movements in the corner of the eye, although perhaps blurred.

Would you like to find out more?

Further topics on the human eye

Do you need further information?

You can contact your regional contact partner via:

You can gladly send us an e-mail or ask your question here

Your data will be handled confidentially. For further information see Data protection declaration.

Products

Projects

Downloads

Planning light

About ERCO

Contact

Inspiration