Non-image forming functions of eyes include the regulation of biological circadian rhythm and biological magnetoreception.Biological magnetoreception means that various organisms including human obtain the direction and position information through the geomagnetic field.Creatures with retina realize magnetoreception regarding retinal cryptochrome as magnetoreceptor.Hypotheses of magnetoreception contain the radical-pair theory and the biological compass theory.The two theories both reckon retinal elements as possible receptor protein of magnetoreception, and eyes as receptor organ.The radical-pair theory suggests that change of radical spin influences the structure of retinal cryptochrome, leading to different downstream chemical reaction products, which makes the variable magnetic field information perceivable.And the biological compass theory proposes a rod-like complex composed of polymerized cryptochromes and magnetoreceptor proteins, which can point to different directions due to light and magnetic signals.These changes in retina transmit geomagnetic field signal to the brain, and then sense of direction is formed.Researching biological magnetoreception promotes a novel perspective in the diagnosis and treatment of eye and brain diseases, and brings innovation in magnetic material field.In this article, non-image forming functions of eyes, hypotheses of magnetoreception and possible mechanism of non-image forming functions of eyes in magnetoreception were reviewed.