It might be subconjunctival hemorrhage. But if the black spots are increasing, then you must consult the ophthalmologist.

It's a subconjunctival bleed. It can occur after a sudden or severe sneeze or cough, heavy lifting, straining, vomiting or even rubbing one's eyes too roughly. It can also occur as a side effect of eye surgery or blood thinners or sudden shoot up of blood pressure. It is mostly self resolving. Usually it disappears within two weeks. Warning signs should be ruled out like pain, diminished vision, floaters means floating mosquito in front of eye etc. Blood pressure should be checked. Avoid rubbing Maintain hygeine Avoid weight lifting. Avoid any strains

Pic of eye would be helpful

Sounds like a subconjunctival Haemorrhage It will go away in 2-3 weeks. Nothing to worry. Kindly get an online consultation to address all your concerns