Adaptation (eye) opsin photopigment. The various cone cells are maximally sensitive to either short wavelengths (blue light), medium wavelengths (green light), or long wavelengths (red light). Rod photoreceptors only contain one type of photopigment, rhodopsin, which has a peak sensitivity at a wavelength of approximately 530 nanometers which corresponds to blue-green light. A minor mechanism of adaptation is the pupillary light reflex, adjusting the amount of light that reaches the retina. In response to varying ambient light levels, rods and cones of eye function both in isolation and in tandem to adjust the visual system. Changes in the sensitivity of rods and
Retina horizontal cell Retina horizontal cell Horizontal cells are the laterally interconnecting neurons having cell bodies in the inner nuclear layer of the retina of vertebrate eyes. They help integrate and regulate the input from multiple photoreceptor cells. Among their functions, horizontal cells are responsible for allowing eyes to adjust to see well under both bright and dim light conditions. Horizontal cells provide inhibitory feedback to rod and cone photoreceptors. Retinal neurons include photoreceptor cells, horizontal cells, bipolar cells, amacrine cells, and ganglion cells. Depending on the species, there are typically one or two classes of horizontal cells, with a third type sometimes