An 18 year old boy comes to the eye casuality with history of injury with a tennis ball. On examination there is no perforation but there is hyphaema. The most likely source of the blood is -
When a blunt object strikes the front of the eye, the eye is quickly shortened in antero-posterior direction and, in a compensating fashion, is stretched laterally. This stretching causes breakage of iris vessels, with blood spilling into the anterior and posterior chamber. The most common source of blood is circulus iridis major.
Iris vessels
Circulus iridis major
Circulus iridis minor
Short posterior ciliary vessels