Postmortem interval, the time elapsed since the death of a body, is critical in determining the investigations of unwitnessed deaths. Therefore, it is a fundamental variable that has been investigated for numerous years. The eye is one of the readiest organs to assess; thus, it becomes very convenient when analyzing a corpse at a crime scene. Several cadaveric phenomena have been described in the eyes, which can be observed in different structures such as the cornea, sclera, iris, lens, vitreous body, retina, and intraocular pressure. These phenomena can, directly and indirectly, contribute to determining the postmortem interval, and so have other quantitative and reproducible elements that collaborate in investigating deaths without witnesses, including deaths in hospitals or at home, and with this to be able to resolve trials. Consequently, in the next chapter, we will review the elements necessary to determine postmortem interval, considering cadaveric phenomena occurring at an ocular level.