Mirrors

I got a review of a lesson in physics on a recent visit to the ophthalmologist. For a moment, I was wondering why the room had 3 mirrors on different places until I realized that they were positioned to reflect the Eye Chart shooting out of the projector:

1. One mirror was directly in front of the projector, which is right beside the patient's seat but angled a bit.
2. One mirror was directly behind, but slightly above, the patient's seat.
3. One mirror was directly in front, but slightly bit above, the patient's seat.

On a purely random note, where do I find a mask resembling the Magic Mirror in Shrek?