"What's that?" Number 3

Humphrey visual field analyser - flashing lights and a button used to check how well you see to the side (the short answer)...or...(the long answer) a computerised instrument which can check the level of brightness at which a flash of light can just be seen, for points all over the visual field. Conditions that can effect the visual field include Glaucoma, Diabetic Retinopathy, stroke, certain tumours aswell as neurological conditions such as MS to name a few. Historically this was performed using a black cloth screen by a "perimetrist" wearing a long black glove, holding a long black "wand" with a small round white tip. The white tip was brought in from the side and the patient reported when they were able to see the white tip. And no, Sooty was not normally involved!! Link here to the full Facebook post.