I have never had this situation, but can offer some general advice that is also applicable to other students whose needs require specialized techniques.
As suggested in other answers here, talk to the student, of course. But ask the student for permission to do at least some of the following.
You probably have a school counselor who can offer some general advice. You can talk to the parents about what they suggest and what has been useful to the student in the past. You can have a meeting with other teachers who have, or had, this student in class to see what they suggest. You may be able, with permission, to talk to the student's former teachers, even in grammar school, to see what might work.
You can also seek, perhaps online, advice from specialists in the student's need-area. The student might, in fact, already be working with a professional. You might see if you can have a conference with them.
As I suggested in a comment, get connected to the APCS community and ask for advice in their fora. Do the same for the ACM SIGCSE group.
It is probably too late to modify your curriculum, though others in your school should do some anticipatory planning for helping this student in the future. It may require some curricular changes generally. I would suggest, however, that curricular updates consider changes that benefit all the students, not just the one.
My go-to suggestion for many things is to incorporate teamwork into the curriculum as much as possible. Every student learns differently, not just the blind student. Every student can contribute to a team, though different students contribute differently. Presumably the student has skills that compensate for lack of sight. Try to bring them to bear in the class so that the student is a part of things, not an outlier. For example, he might have an exceptional memory or an exceptional organizational ability. All of these are needed by professionals and can be capitalized on in the classroom.
In taking APCS the student is obviously not looking for an easy way out. But do what you can to make the classroom a supportive community that benefits all students.