In retinoscopy with plane mirror at 1 meter distance, if retinal glow moves in opposite direction of the mirror, the person has myopia of
**Core Concept**
The underlying principle being tested is the technique of retinoscopy, which is used to determine the refractive error of an eye. In retinoscopy, a plane mirror is used to reflect light into the patient's eye, and the reflection, or retinal glow, is observed. The movement of the retinal glow in relation to the movement of the mirror helps in determining whether the patient is myopic, hyperopic, or emmetropic.
**Why the Correct Answer is Right**
When the retinal glow moves in the opposite direction of the mirror, it indicates that the patient is myopic. This is because in myopia, the focal point of light falls in front of the retina, causing the retinal glow to appear to move in the opposite direction of the mirror movement. The distance of the mirror, in this case, 1 meter, is used to calculate the degree of myopia.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the degree of myopia is not accurately represented.
**Option B:** This option is also incorrect as it does not correctly correlate with the movement of the retinal glow in retinoscopy.
**Option C:** This option is incorrect as the relationship between the movement of the retinal glow and the degree of myopia is not accurately described.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the movement of the retinal glow against the movement of the mirror indicates myopia, while a movement with the mirror suggests hyperopia. This principle is crucial in retinoscopy for determining the type and degree of refractive error.
**Correct Answer:** Correct Answer: D. Low myopia