Stimulus modality lit area, the eyes require time for a good quantity of rhodopsin to regenerate. As more time passes, there is a higher chance that the photons will split an unbleached photopigment because the rate of regeneration will have surpassed the rate of bleaching. This is called adaptation. Humans are able to see an array of colours because light in the visible spectrum is made up of different wavelengths (from 380 to 760 nm). Our ability to see in colour is due to three different cone cells in the retina, containing three different photopigments. The three cones are each specialized to
Retina 500,000 bits per second (for more information on bits, see information theory) without colour or around 600,000 bits per second including colour. When the retina sends neural impulses representing an image to the brain, it spatially encodes (compresses) those impulses to fit the limited capacity of the optic nerve. Compression is necessary because there are 100 times more photoreceptor cells than ganglion cells. This is done by "decorrelation", which is carried out by the "centre–surround structures", which are implemented by the bipolar and ganglion cells. There are two types of centre–surround structures in the retina – on-centres and off-centres. On-centres