Tech: Remote vision testing - Ancient, modern, and in between

David Baker’s excellent article described how more than a thousand years ago the night sky was used to test eyesight. Effectively one of the eyesight forms of remote vision testing. Thinking about it, the test has everything required: totally repeatable; no differences irrespective of who performs it or where; independent of language or culture; total control over viewing distance; no big difference if your patient leans forward a little; and free at point of delivery.

So why do we need anything else? Well, it would be good to have control over contrast. Practitioners would be at the whim of the weather. And the working hours would not suit everyone.