Unusual vision: nerve cells in the eye that detect light for the body’s internal clock

A novel photoreceptor in the mammalian retina has been characterized, likely using melanopsin.

• These cells differ significantly from traditional rod and cone photoreceptors.
• They exhibit lower sensitivity and spatiotemporal resolution compared to rods and cones.
• These photoreceptors are likely specialized for encoding ambient light intensity.
• They are classified as ganglion cells, allowing direct communication with the brain.
• They may play a role in synchronizing circadian rhythms with the solar day.
• They also contribute to the pupillary light reflex and other responses to light.

Simplified