Patent ID: 8272740

Claim:
A calibration plate for calibrating a retinoscope having a handle, a lamp housed within a power capsule with a calibration line located thereon, a lens located above the lamp, a thumb-slide for sliding the power capsule housing the lamp, said calibration plate comprising: a flat piece of material having a front surface and a rear surface; at least one calibration line located on the front surface; an attachment means for attaching said calibration plate to a side portion of the retinoscope; said calibration plate being capable of sliding up or down via an adjustment means that allows a user to adjust the calibration plate on the retinoscope so the at least one calibration line located on the front surface of the calibration plate is in alignment with the calibration line located on the power capsule; a slide bar attached to the retinoscope and located below to the thumb-slide via an attachment means; and said slide bar being capable of sliding up or down via an adjustment means that allows a user to position a top edge of the slide bar at a predetermined location below the thumb-slide to prevent the thumb-slide from moving lower than the top edge of the slide bar.