Where is posterior subcapsular cataract located within the lens?

• A. In the anterior lens cortex.
• B. In the posterior capsule's far periphery.
• C. In the lens cortex.
• D. In the posterior subcapsular region near the posterior capsule.

Answer: (D)

The key idea is that posterior subcapsular cataracts form in the area just in front of the back boundary of the lens, i.e., the posterior subcapsular region near the posterior capsule. This location lies directly beneath the posterior capsule, in the back part of the lens, where abnormal lens epithelial cells can migrate and aggregate to create an opacity. Because the opacity sits at the back of the lens, it can disproportionately disturb vision, especially with glare and bright light, even when the rest of the lens looks relatively clear. It is not in the anterior cortex or the general cortical area, and it is not located in the far periphery of the posterior capsule; the defining feature is its position right under the posterior capsule in the posterior subcapsular zone.