Ok. I would say the vision and albinism are probably connected and MAY account for some of his reading and writing difficulties. Every child is different. My boys (non-id twins) both have it. One has just started to read a tiny bit and write his name. The other can't. But, like I say, they have other problems too.
The main things I've read about having albinism is generally it means reduced pigment in the eye, which usually causes nystagmus (wobbly eyes). So even with glasses, if your son has this, his vision will be compromised.
He will probably need to sit at the front of the class to see things like white-boards, etc.
As he gets older and learns to read, he will probably need a larger font to look at than other children.
Find out if there is a local Visual Impairment Team that can come and help. Ring the Council. They should be able to point you in the right direction. Or Social Services. Or a local Children With Disabilities Team.
Get a referral to the Eye Hospital via the people/doctors you've already been in touch with.
It's only now my sons are 7 that I've finally got to know they need to see things 6 or 7 times bigger than another child. That was after an appointment at the Eye Hospital Low Vision Unit.
Good luck, x