**Core Concept**
Blindness in children is a significant concern worldwide, and various causes can be attributed to its development. Keratomalacia is a condition characterized by softening of the cornea due to vitamin A deficiency, leading to corneal ulcers and potentially resulting in permanent blindness.

**Why the Correct Answer is Right**
Keratomalacia is the most common cause of childhood blindness globally. Vitamin A deficiency is a significant risk factor for this condition, particularly in areas with limited access to nutrition and healthcare. When vitamin A levels are low, the cornea becomes vulnerable to damage, leading to corneal ulcers and subsequent blindness. In children, vitamin A deficiency can be caused by inadequate diet, malabsorption, or increased requirements during rapid growth and development.

**Why Each Wrong Option is Incorrect**
**Option B:** Congenital cataract is a significant cause of blindness in children, but it is not the most common cause. Congenital cataracts are present at birth and can be caused by genetic mutations, infections, or environmental factors.

**Option C:** Glaucoma is a group of eye conditions that can cause blindness, but it is not the most common cause in children. Glaucoma is typically associated with increased intraocular pressure, which can damage the optic nerve and lead to vision loss.

**Option D:** Injuries are a significant cause of blindness in children, but they are not the most common cause. Injuries can result in trauma to the eye, leading to various conditions such as retinal detachment, cataracts, or glaucoma.

**Clinical Pearl / High-Yield Fact**
It is essential to note that vitamin A deficiency is a preventable cause of childhood blindness. Ensuring adequate nutrition, particularly in areas with limited access to healthcare, can significantly reduce the incidence of keratomalacia and subsequent blindness.

**Correct Answer Line**
✓ Correct Answer: A. Keratomalacia.