Final answer:
In retinoscopy, 'against motion' is observed in myopic patients because the light reflects from the retina in the opposite direction of the retinoscope. However, 'within your working distance', the light rays entering the eye are considered diverging, simulating the focusing point of myopic eye and resulting in 'with motion' during retinoscopy.
Step-by-step explanation:
Retinoscopy is a technique used by optometrists and ophthalmologists to estimate a patient's refractive error and the need for glasses, if any. The concept behind retinoscopy involves introducing light into the patient's eye and observing the reflex, or the light that bounces off the inner part of the eye, the retina.
In a myopic patient (a patient with shortsightedness), light coming from distant objects forms an image in front of the retina instead of directly on it. Thus, when performing retinoscopy on a myopic patient, the examiner sees 'against motion'. This is due to the light reflecting from the retina moving in the opposite direction to the movement of the retinoscope.
However, 'within your working distance' signifies that the light source is moved closer to the patient's eye (within one meter) in this context. At this close distance, the light rays entering the eye are considered diverging rather than parallel. In hypothesis, this simulates the point where the myopic eye can create a focused image—a point in front of the retina—resulting in motion' during the retinoscopy process.
Learn more about Retinoscopy