black specks floating on cornea

Are you seeing black specks or are there actually black speck there?

If there are specks in your vision then it could be a form of age related "floaters" where changes within your eyeball cause tiny collagen strands in the vitreous jelly to cast shadows on your retina - so you see spots.

Are you suffering any loss of sight apart from the spots? Have you been to your optician for an eye examination?

Dehydration is one cause but often they seem to go away on their own.

Yes, Cold Have had recent eye test (to renew driving permit). Doctor not very concerned about my problem. They are simply "floaters". Not serious but annoying.

Had floaters all my life some weirdly shaped one sometimes
They don’t bother me I kind of forget about them most of the time