We are offering distance vision chart .cat no. Ibl-3311, ibl-3312(distance vision chart reverse)reverse letter visual acuity test chart is designed to be read by the patient through an ophthalmic viewing mirror in order to achieve a greater viewing distance. It is best used when exam room space is too limited for a regular 20ft distance eye chart (ibl-3310) and this reverse letter chart is an exact mirror image of that classic eye chart. reverse letter visual acuity test chart is made of extra strong, non-reflecting, matte finish cardboard, with a brass eyelet for wall mounting. Red and green bars not only serve as a reference point, but also hint as to a patient's color perception.