The vet said his dog needed to take special medicines for his eyes
Why would it need to take medicine for its eyes?
He said his eyes are very dry, apparently it could harm his sight soon
It sounds like he should follow his vet's advice then! Pet owners are expected to take care of the health of their pets.  Doing otherwise would be cruel!
This is terrible! Do you know how much this would cost?!
Cost can be problematic, sure. If they can't afford it they can set up a GoFundMe to raise enough money for the operation.