Adaptation refers to the ability of the eye to adjust to changes in lighting conditions. There are two types of adaptation: dark adaptation and light adaptation. Dark adaptation is the process by which the eye adjusts to low light levels, and it involves the regeneration of the visual pigment from opsin and 11-cis retinal. The time required for dark adaptation and pigment regeneration is largely determined by the local concentration of 11-cis retinal and the rate at which it is delivered to the opsin in the bleached rods. Rods are more sensitive to light and take longer to fully adapt to the change in light. Cones, on the other hand, take approximately 9-10 minutes to adapt to the dark. The sensitivity of the rod pathway improves considerably within 5-10 minutes in the dark. Inhibition by neurons also affects activation in synapses. Together with the bleaching of a rod or cone pigment, merging of signals on ganglion cells are inhibited, reducing convergence.