A patient with normal vision and normal hearing can describe the individual letter-shapes on a page perfectly well, but cannot make any sense of written words as language; his spoken language comprehension and production are entirely normal. What is this?

This is agnostic alexia: vision is intact, and written words cannot be understood as language despite being clearly seen, while spoken language comprehension and production remain preserved, exactly as described. It is not pure word deafness, since agnostic alexia differs from pure word deafness in affecting written rather than spoken language comprehension. It is not visual asymbolia, since agnostic alexia differs from visual asymbolia specifically in the inability to copy writing, which is at least partially preserved in visual asymbolia. And it is not nominal aphasia, which is a naming difficulty within otherwise fluent, comprehensible speech, not a written-language comprehension failure.