What type of dog is it??
How old is he?
Try looking in your dogs eye could
there be a hair or dirt in its eye?
Wipe with warm water and an soft cloth,some say saline water to clean it if its conjunctivitis.
is the whites of his eye red?
swollen,is he squinting,trying to rub his eye on cushions,bed,paws.
Does his eye lashes look like there turning in?
He's a Jack Russell, just over 3 years old, I've been wiping his eyes with warm water he's starting to get it now without resting or sleeping, his eyes are still dark no redness and he's not at his eyes anymore than usual his eyelashes seem fine also, he's still a young dog so I doubt it's catarachts any ideas??