You could argue that the 'keen eyesight' would make it more sensitive to shiz like Flash. It's not really a 'lowering of accuracy' per se, just a flash of light that distracts targets in general. It's not like you're going to lose this matchup :p
Also Happy Birthday!
Sableye: (Dark/Ghost) - See Ghost Pokémon rules, all Ghosts fight more enthusiastically at night, though light does not hinder their ability to battle. Sableye can see in the dark. Due to their keen eyesight, Sableye's accuracy cannot be lowered - Sableye is permanently solid, unable to achieve other forms. Due to Ghost not providing immunity against Fighting attacks, they are considered weak to Fighting.
Just wondering how the eyesight cannot be lowered thing factors in.