How do bull shark eyes work?

Tapetum lucidum: This is a layer of tissue behind the retina that reflects light back into the eye, increasing the amount of light available to the photoreceptor cells. This helps bull sharks to see in low-light conditions, such as at night or in deep water.

Rod cells: These photoreceptor cells are sensitive to low levels of light, making them well-suited for seeing in dark environments. Bull sharks have a high density of rod cells in their retinas, which gives them excellent night vision.

Cone cells: These photoreceptor cells are responsible for color vision and are most sensitive to bright light. Bull sharks have fewer cone cells than other sharks, which means that they have poor color vision. However, they can still distinguish between different shades of gray, which is helpful for hunting in low-light conditions.

Nictitating membrane: This is a transparent membrane that can be drawn over the eye to protect it from damage. Bull sharks have a nictitating membrane that is especially thick and strong, which helps to protect their eyes from the sharp teeth of their prey.