There are 2 types of photoreceptors rods and cones they react to light in different ways.
Rods-
Respond to low levels of light and are primary responsible for night vision.
They are poor at detecting fine details in an image and are not involved in colour vision.
Cones-
Respond to high levels of light and are primary responsible for our vision in well-lit conditions.
They detect fine details and are responsible for colour vision.
