 Cats have excellent night vision and can see at only one @-@ sixth the light level required for human vision . This is partly the result of cat eyes having a tapetum lucidum , which reflects any light that passes through the retina back into the eye , thereby increasing the eye 's sensitivity to dim light . Another adaptation to dim light is the large pupils of cats ' eyes . Unlike some big cats , such as tigers , domestic cats have slit pupils . These slit pupils can focus bright light without chromatic aberration , and are needed since the domestic cat 's pupils are much larger , relative to their eyes , than the pupils of the big cats . At low light levels a cat 's pupils will expand to cover most of the exposed surface of its eyes . However , domestic cats have rather poor color vision and ( like most <unk> mammals ) have only two types of cones , optimized for sensitivity to blue and yellowish green ; they have limited ability to distinguish between red and green . A 1993 paper reported a response to middle wavelengths from a system other than the rods which might be due to a third type of cone . However , this appears to be an adaptation to low light levels rather than representing true trichromatic vision . 
