Vision in the dark

For humans, seeing in the dark is a major challenge, yet other animals live their entire lives in darkness and seemingly have no trouble negotiating the world around them. So why is it that humans struggle in low light while many animals thrive? Exactly why is darkness a challenge for vision and how can these challenges be overcome?

In essence vision is all about the eye capturing photons, the fundamental particles of light, to form a picture of the world. Light-sensitive photoreceptor cells in the retina of the eye absorb photons, which trigger a neuronal response that, through various neurological processes, is interpreted by the brain as vision. However, photoreceptors are not perfect; they are inherently noisy due to spontaneous activation of the photopigment in the cells. This activation produces a signal that is indistinguishable from the signal that the photoreceptors produce when activated by photons.