Hyphema

Hyphema (from Greek ὑπό hypo ( under ) and αἷμα haima (blood) ) is in ophthalmology, a collection of blood in the anterior chamber. You may be a result of injury, acute hemorrhagic iritis or infection. Upright head position, the blood collection shows the hyphema as a horizontal mirror.

Position of the blood collection - schematic section through the eye