Unlike Rods, which are the other type of photoreceptor in the eye, cone cells function in high light levels and allow us to see in colour and refine our vision during the day.
Cone cells contain three photopigments unlike rod cells which just contain one, Rhodopsin, and these three pigments are stimulated at different wavelengths of light, which allow us to see in colour.
The area of the retina with the highest density of cone cells is the fovea, which is also the area of sharpest vision.
Cone cells are made up of three segments:
- Outer Segment - This section contains the photopigments in membranous disks and so this is where light transduction takes place.
- Inner Segment - This is where the cells organelles are located and so all the metabolic processes of the cell take place here, including the synthesis of the photopigments.
- Synaptic Terminal - This is where the cone cell communicates with neighbouring bipolar cells.
- ↑ Silverthorn (2013) Human Physiology: An Integrated Approach, United States of America: Pearson (Pages 365-66)