Well if you register as partially sighted then i imagine you'd be entitled to all sorts of benefits and medical help, i really don't see that there would be any disadvantages.
I know its completly differnt, but i am registered a partiarly deaf.
As far as i know you are entitled to a social worker type person, who will look outfor you best needs. You can also claim loads of equipment which might help you in your day to day life. Things like large print items and items which might help around the home.
I dont know your age, but if you go to uni or anything the you are ntitled to disabled students allowence. Which generally gives you more support. You would be funded to have someone sit with you in lesson and take notes for you. As well as things like computers.
I wouldnt say there are any disadvanges to it. Its a scheme which is there to help you.
You can also arrange for things like letters from the bank to be sent to you in large print.
Hope that helps.
Feel free to pm me if you want any more info.
Kim
on of my friends is registered partially sighted, an hasnt been able to drive, but theyve just discovered that theres a operation they could do that would cure it.