Music students spend a lot of time studying musical notation, terminology, and theory. Of course, many musicians don't read music while they perform, so this emphasis on reading is obviously not related to one's ability to play their instrument. Rather, it's about learning the language that musicians use to communicate, and that is an important part of music education that we shouldn't neglect.
However, some beginners aren't able to read music, or they aren't able to learn to do so using traditional methods. It is therefore necessary to allow them to adapt, whether that means learning entirely by ear or approaching notation differently.
Binocular vision dysfunction (BVD) is a condition in which the eyes are slightly misaligned. The eye muscles work harder to compensate, and that causes eye strain, double vision, depth perception issues, headaches, dizziness, and difficulty reading.
BVD is typically treated with reading glasses that include prism correction. However, this is a problem for musicians because the distance from their eyes to the music stand is greater than that the distance from their eyes to the text when reading a book or mobile device. BVD causes you to lose your place while reading, especially when trying to follow a repeat or find the beginning of the next line. The longer the piece, the greater the likelihood that the eyes will get tired and stop cooperating.
A beginner with BVD will often have no difficulty understanding how to read music. If they don't know that they have the condition or if they don't begin struggling until their repertoire and practice sessions become longer, they might play for months or years before they begin to realize there is a problem. Since people with BVD may have been diagnosed with migraines, they might assume the vision problems are a symptom of a migraine rather than a possible cause, an assumption that will be confirmed by the fact that treating the migraine will also mean allowing their eyes to relax, providing relief from the BVD symptoms.
Musicians with BVD might be more comfortable memorizing their music before a performance, since relying on the score includes a risk of losing their place. They might also find ways to help them better navigate repeats, such as circling or highlighting them. Writing in music with anything but a pencil is traditionally discouraged because you might need to make changes or might not own the music. However, colors might be the only thing that makes a beginner with BVD comfortable when reading the score. If writing in the music with something permanent is a problem, make a photocopy or use digital sheet music in order to accommodate the student.