The cone-shaped pigment cells in the retina of the eye are called cone cells. It contains purple pigments called iodopsin and cyanopsin. It contains a protein called photopsin. Its number is about 60-70 lakhs. Each angle cell is 40 micrometers long and 3-5 micrometers thick. It contains three types of cells. Red, green and blue cells. It is suitable for viewing in bright light. White color is seen when three types of angles are equally excited. Color blindness occurs when the cornea is destroyed.