Quote Originally Posted by hbvision View Post
For anyone capable of using FOSS (free open source software) there is this:

I'll be setting it up on a Raspberry Pi with a usb remote. Expect it to cost $250 with monitor, mount, cables, remote.
I'll write back once I have it tested.
Most modern televisions - especially large screen televisions - have a USB port. These are typically used for firmware updates. However, it is also possible to place images on to USB drives and have them play on the television. For example, on my very inexpensive LCD TV, I have to change the TV's 'Source' to 'USB' - then I can browse the images on the USB drive using the remote control.

It would seem that such a solution would work for displaying eye testing charts by displaying the eye charts in whatever software creates them, and then taking screen shots and saving those to the USB drive.