...patient blinded in a bomb blast? I know that's really specific, but I'm writing a scene in a play! Simple tests not involving any big equipment would be best, please.

He'd say -'can you read the chart' I said, CAN YOU READ THE CHART!'

How true, how true. They did that to me when my left eye was out of commission. Most pointless thing ever when it can't even see the room......

Mostly it's look up, look down, look left... and so on while they use a some form of scope to peer into the eye.