**Core Concept**
Phacomorphic glaucoma is a type of secondary glaucoma caused by the mechanical blockage of the anterior chamber angle by an intumescent lens (i.e., a lens that has become swollen and expanded due to age-related changes or other conditions). This leads to increased intraocular pressure (IOP) and potential optic nerve damage.

**Why the Correct Answer is Right**
Phacomorphic glaucoma is associated with cataract formation due to the lens swelling and hardening, which can occur in conditions such as age-related cataract or after cataract surgery complications. The swollen lens can push against the iris, causing it to become apposed to the cornea and blocking the drainage of aqueous humor from the eye. This leads to a rapid increase in IOP, which is characteristic of phacomorphic glaucoma. The condition is often seen in patients with mature or hypermature cataracts.

**Why Each Wrong Option is Incorrect**
**Option B:** Neovascular glaucoma is a type of secondary glaucoma caused by the growth of new blood vessels on the iris and trabecular meshwork, leading to increased IOP. It is often associated with conditions such as diabetic retinopathy, but not specifically with cataract formation.

**Option C:** Phacoanaphylactic glaucoma is a rare form of secondary glaucoma that occurs after cataract surgery, typically due to an immune response to lens proteins. While it can be associated with cataract surgery, it is not directly caused by cataract formation.

**Option D:** Buphthalmos is a condition characterized by an enlarged eyeball in infants and young children, often due to congenital glaucoma. It is not directly associated with cataract formation.

**Clinical Pearl / High-Yield Fact**
Remember the mnemonic "P-I-O" to differentiate between phacomorphic glaucoma (P), phacoanaphylactic glaucoma (I), and other forms of glaucoma: Phacomorphic glaucoma is caused by the lens (P), Phacoanaphylactic glaucoma is an immune response (I), and other forms of glaucoma can be classified based on their underlying causes.

**✓ Correct Answer: A. Phacomorphic glaucoma**