A spontaneous, non-painful, non-vision affecting red eye is usually secondary to a conjunctival hemorrhage. This is when blood spots obscure the white of your eye. The eye’s conjunctiva contains a lot of small blood vessels that can rupture. When they break, you get a bright red spot that is visible to people. Often times you are unaware of this, and your attention to it is called out by others.
The common causes of conjunctival hemorrhage may include, but are not limited to:
Conjunctival hemorrhage usually resolves on its own within a few days to a few weeks, depending on its size. It is often painless, although some foreign body sensation may be felt.
Supportive treatment with ophthalmic lubricants (tear supplements) may provide comfort. Application of a cold compress within the first day may assist clotting. Application of warm compress onwards may assist resolution. The bright red color will spread inferiorly due to gravity, and may involve the entire eyeball, depending on the size of the conjunctival vessel that ruptured. It will change from red, to brown, to yellow, to gray over a week or two.