Under very dim levels of illumination foveas react to increase the sensitivity of the optic nerve. rods are more light-sensitive than cones. feature detectors in the retina activate. rods fire according to place theory to perceive the available light. the iris expands to allow more light to reach the retina.

The Human Eye:

Human eye is considered one of the most delicate, along with being the most complex body organ. It contains the system of specialized cells which can receive different wavelengths or spectrum of colors and then translate or convert these spectrum of colors into the electric signals or charges which represents the different set of information or data regarding the identification of each object and color that it holds. As, the eye is directly connected to the brain and whole nervous system of the human body, while the information received by the brain is analyzed and then sent back to the eye for further operations.However, like any advanced form of camera the human eye is composed of a complex form lens and for the identification of different colors and objects. As, the rods and cons are there to serve different purposes for the eye, the first one is for performing the eye operations in the dim lights while the cons are there for having a more variety or complex form of information about the different spectrum that are received by the eyes. While, the conversion of these spectrum into the data or relevant information is the main purpose of the human eye. The fovea is is the part of the retina which is comprised of the "cons" , as they are there to evaluate the different spectrum and wavelengths received by the eye in a more high beam light. While, the nerves are connected to the eyes, in order to analyze the information inside the brain. The aperture which is either becomes smaller in size or enlarges in diameter is called as the pupil inside the eye. While, the eye has the different small muscles which are there for the contraction and relaxation purposes of the pupil inside the eye. We can just say that it acts as the tunnel or passage way for the transmission of the signals inside the eye.