And for one family, that's a common complaint.
Meet the Timbangs.
They live in Tarlac, about two hours' drive north of Manila, in the Philippines.
The Timbangs have a rare genetic form of cataracts that has left three generations partially blind.
In 25 years, the Fred Hollows Foundation has never had a case like this, with so many members of a family affected.
"The kids are lucky if they can finish grade 6 because they can't even see the blackboard," grandmother Iluminada Timbang Paculanan said.
