retina

Everyday

The retina is the thin layer at the back of the inside of the eye that senses light and sends messages to the brain. tree →

In the lessons

In science, light enters through the pupil, the lens focuses it on the retina, and the optic nerve takes the signal to the brain. The image on the retina is upside down; the brain turns it round. Rods see in dim light; cones see colour.

Examples

• The retina is at the back of your eye. tree →
• Light makes a picture on the retina. tree →
• Never look at the sun — it can damage your retina. tree →
• The optician shone a light to check my retina. tree →
• The retina has cells called rods and cones. tree →
• The brain flips the picture from the retina. tree →

Note

Countable. Plural retinas (doctors also say retinae). Not the same as the iris (the coloured part).