A tiger's night vision is six times more powerful than a human's.

Tigers are crepuscular hunters, meaning they are most active during dawn and dusk. To thrive in low-light conditions, their eyes have evolved a biological mirror called the tapetum lucidum. This layer of tissue is located behind the retina and reflects visible light back through the photoreceptors. This effectively gives the retina a second chance to absorb photons that were missed on the first pass.While humans have a high concentration of cone cells for color vision, tigers possess a much higher density of rod cells. Rod cells are extremely sensitive to light and motion but do not detect color well. Research by zoologists indicates that this combination allows tigers to see clearly in light levels that are only 1/6th of what a human requires to see anything at all.The glowing effect seen in photographs or under spotlights is known as eyeshine. This occurs when light reflects off the tapetum lucidum and exits the eye. Interestingly, the color of the glow can vary by species, but in tigers, it typically appears as a brilliant golden or greenish-yellow. This adaptation is a key reason why tigers have a hunting success rate that remains high even in dense, dark jungles.Beyond the tapetum lucidum, tigers have large pupils that can dilate significantly more than human pupils. This physical expansion allows even more ambient light to enter the eye. When combined with their sensitive whiskers and acute hearing, their visual prowess makes them one of nature's most effective nocturnal predators. Studies from the Smithsonian National Zoo confirm these adaptations are vital for their survival in the wild.