The inferior fornix of the eye is the potential space between the lower eyelid and the eyeball, or the white of the eye, which is called the inferior fornix. The corresponding space between the upper eyelid and the white of the eye is called the superior fornix. The posterior ends of the two foramina are blind and do not lead to the posterior part of the eye. Their opening is the upper and lower eyelids forming a transverse part called the lid fissure, which is a sac-like gap called the conjunctival sac with a bag-like structure, foreign bodies in the eye, and tears circulating back and forth. Therefore, some people would have been more worried about, for example, whether eyelashes falling into the eye would run into the eyeball, behind the eyeball, or flying insects going in, but in fact, there is no need to worry because they are completely unconnected to the inside of the eye backwards.