**Core Concept**
Diabetic cataract is a type of cataract that occurs in patients with diabetes mellitus, characterized by the accumulation of sorbitol and other sugar alcohols in the lens of the eye due to the enzyme aldose reductase. This leads to osmotic changes and ultimately to lens opacification.

**Why the Correct Answer is Right**
The accumulation of sorbitol in the lens is a result of the polyol pathway, which is activated when glucose levels are high. Aldose reductase, the enzyme responsible for this reaction, converts excess glucose into sorbitol, which then accumulates in the lens and causes osmotic changes. This leads to water influx into the lens, causing it to swell and eventually leading to lens opacification. The polyol pathway is a key mechanism in the development of diabetic cataract.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not mention the specific mechanism of diabetic cataract formation through the polyol pathway and aldose reductase.
**Option B:** This option is incorrect because it does not accurately describe the pathophysiology of diabetic cataract, which is related to the accumulation of sorbitol in the lens, not the breakdown of lens proteins.
**Option C:** This option is incorrect because it does not specifically relate to the pathophysiology of diabetic cataract and is more general.

**Clinical Pearl / High-Yield Fact**
The use of aldose reductase inhibitors has been explored as a potential treatment for diabetic cataract, by reducing the accumulation of sorbitol in the lens and slowing the progression of lens opacification.

**Correct Answer: D.**