This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
All of the following are common causes of childhood blindness, EXCEPT: 
Select and explain. 
A. Congenital rubella, B. Toxoplasmosis, C. Ophthalmia neonatorum, D. Congenital dacryocystitis
D: Congenital dacryocystitis
Answer: D: Congenital dacryocystitis 
Explanation: The common causes of childhood blindness that affects the retina are hereditary dystrophies, retinopathy of immaturity and toxoplasmosis. Corneal blindness could be due to vitamin A deficiency, measles and Ophthalmia neonatorum. Congenital rubella affects the lens of the eye. Other congenital conditions and coical blindness can also attribute to blindness in children. Ref: Pediatric Retina: Medical and Surgical Approaches, Mary Elizabeth Hanett, M.D., Page: 318