The retina contains special neurons that are able to detect light and convert it into electrical signals that can be sent to the brain. These neurons are called photoreceptors. There are two types of photoreceptor cells:
- Rods
- Cones
Rods are photoreceptor cells that are very sensitive to light, so they are able to function better under low light conditions. They are about 500 – 1000 times more sensitive to light than cones. These cells enable us to have good vision with low light. They are located on the outer areas of the retina.
Cones are the reason why we can see different colors. They are located in the center of the retina in an area called the fovea centralis and near the macula. Cones can be divided into three different types:
- 60% are red-sensing cones
- 30% are green-sensing cones
- 10% are blue-sensing cones