<<<<homonymous hemianopsia>>>> - but what is it?


-- "anopsia" is blindness

-- "hemianopisa" is blindness in one-half the visual field, either the right (or left) half,
or perhaps the top (or bottom) half

-- "homonymous hemianopsia" is blindness in the _same_ half of the visual field in both eyes, (e.g. "right homonymous hemianopsia"). It is also possible to be unable to see the inner half of the visual field in both eyes.

The distinction can be helpful in localizing the part of the brain that is causing the blindness - right in front where the optic nerves are, say, as opposed to the back part which identifies the nerve impulses as images.