**Core Concept**
Sudden induced hypermetropia refers to a sudden increase in the refractive power of the eye, resulting in a shift towards hypermetropia (farsightedness). This condition is often associated with changes in the shape or structure of the eye, particularly in the lens or cornea.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of sudden induced hypermetropia, which can occur due to a condition called posterior subcapsular cataract. In this condition, a small area of opacity forms in the posterior subcapsular region of the lens, causing the lens to become thicker and more convex, leading to an increase in refractive power and resulting in hypermetropia. This is because the opacity blocks the normal flow of light through the lens, causing the lens to become more curved to compensate for the obstruction.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might refer to a condition such as uveitis, which can cause changes in vision but is not typically associated with sudden induced hypermetropia.
**Option B:** This option might refer to a condition such as keratoconus, which is a progressive thinning of the cornea, but it is not typically associated with sudden induced hypermetropia.
**Option C:** This option might refer to a condition such as presbyopia, which is a age-related loss of near vision, but it is not typically associated with sudden induced hypermetropia.

**Clinical Pearl / High-Yield Fact**
A posterior subcapsular cataract can be a risk factor for the development of posterior capsular opacification, a complication that can occur after cataract surgery. It is essential to monitor patients with posterior subcapsular cataracts closely for signs of this complication.

**Correct Answer:** C. Posterior subcapsular cataract.