Sharks use up to seven senses to navigate their environment. One of them is sight, and shark eyes are designed differently depending on the species and their life habits.
Although sharks have poor color vision, they are incredibly good at recognizing contrasts, and each species has a 360-degree field of view. Sharks have a dynamic iris that has the ability to dilate the pupil in dark and narrow it in bright conditions.
Some species have a yellowish pigment in their eyes that filters UV light for protection from the sun in shallow habitats. This pigment is actually a result of the enzymatic oxidation of tryptophan.
The function of the unique reflective coating (“tapetum lucidum”) in the pupil of the eye is to increase the sensitivity of shark eyes to dark environments.