In the episode Monk up all night first aired on 9/14/07 Monk finally meets the woman who has haunted his thoughts right after she bumped into him randomly on the street in the first scene.

Later when he meets her face to face in the second to last scene it turns out that she received a corneal transplant from Monks wife right after she died. The disease the woman was going blind from was retinitis pigmentosa, which is a retinal disease not corneal and it makes no sense that a corneal transplant would have been done