Amsler sign also known as Amsler-Verrey sign is the name of the diagnostic finding seen in patients with Fuchs heterochromic iridocyclitis (FHI). It is described as presence of blood (hyphema) in the aspirated vitreous fluid, in paracentesis of the anterior chamber, and is caused due to iris atrophy usually seen in FHI and exposure of the fragile iris vasculature to the vitreous fluid. The sudden change of pressure in the anterior chamber upon suction induced by the paracentesis, or during a cataract surgery, causes bursting of the fragile superficial iris capillaries resultsing in micro-bleeding. This is one clinical diagnostic sign of FHI.