After my long and sordid career as a mother (read: 10 years), I've ascertained that certain kids are prone to certain ailments. My eldest had a propensity toward lung issues. My baby, well, she was born with a neural tube defect. My middle son, Alex, oddly has had problems with his eyes.
From that description, you might think that he'd been born partially blind, or with a lazy eye, or is cross-eyed or something, and you'd think that I'm only capable of making weird kids. (Which is, in fact, true.) But in this case, it's a moot point. Because Alex's eye issues are all accidental.