Night vision is the ability to see in low-light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum. Where cat vision really shines is at night; cats have six to eight times more rod cells, which can detect light at low levels, than humans do.
