Complex sentence: This proved not to be the case but he suffered from eye strain and impairment to his vision for much of his life and this was a major reason for his decision to retire from St Paul's Cathedral in 1888.
Split into simpler sentences: This proved not to be the case, but he suffered from eye strain and impairment to his vision for much of his life. This was a major reason for his decision to retire from St Paul's Cathedral in 1888.