On performing refraction using plane mirror on a patient who’s has a refractive error of -3 D sphere with -2 D cylinder at 90 degree from a distance 1 metre under no cyclopgia, the reflex would be seen to move
**Core Concept**
The question tests the understanding of retinoscopy, a technique used to determine the refractive error of an eye. Retinoscopy involves shining a light into the eye and observing the reflection. The movement of the reflex is used to estimate the refractive error. **Refraction** and **retinoscopy** are key concepts here.
**Why the Correct Answer is Right**
Since the patient has a refractive error of -3 D sphere with -2 D cylinder at 90 degrees, the light reflex will move in a specific direction when the retinoscopy is performed. The **against movement** is seen in **myopic** eyes, which is the case here due to the negative spherical error. The cylindrical error at 90 degrees also affects the reflex movement.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not match the expected movement for the given refractive error.
**Option B:** Similarly, this option does not align with the refractive error provided.
**Option C:** This option is also incorrect as it does not correspond to the movement expected for a myopic eye with the specified cylindrical error.
**Clinical Pearl / High-Yield Fact**
In retinoscopy, the direction of the reflex movement is crucial for determining the type and amount of refractive error. Remembering that **against movement** indicates **myopia** and **with movement** indicates **hypermetropia** is key.
**Correct Answer:** D. Against movement