An adjustable frame that holds trial lenses used during retinoscopy or refraction tests on the eye.  2 main kind of Trial frames: PD fixed trial frames and Adjustable trial frame both them with axis routation disc to measure the astigmatism axis and several lens holders. A simple trial frame is used with a retinoscope to determine refractive errors. Lens of varying focal lengths may be placed in the trial frame,  Famous Trial frame maker: Oculus and Topcon products own the majority market, all of our trial frame are the replica from them.