A Life's Eclipse — George Manville Fenn

The hero is John Grange, a young gardener on Mrs. Mostyn's estate, who finds himself to be in love with Mary Ellis, the daughter of the bailiff, James Ellis. But as he is no more than an under-gardener Ellis is angry with him for even thinking of Mary.
There is an accident when John has ascended a large cedar tree that had lost a bough in a gale, and a broken branch needed to be tidied up. John falls from where he was sawing, onto the ground, landing on his head. He recovers from the concussion, but is now blind.
His rival not only for Mary's hand but also for promotion to Head Gardener when Dunton, the present Head Gardener, now very old, dies, is Daniel Barnett, who of course gets the job. But he is a nasty man, not very good at his work, while the blind John can do his work almost as well as before, working by touch. Barnett plays a number of most unkind tricks on his rival John. Eventually John disappears without trace and rumour is rife