I have a burst blood vessel above my left eye ball. it has just appeared, it doesn't hurt?

Capillary bleed: These can appear on the white part of the eyeball, the sclera, quite spontaneously, are painless, and usually resolve with no injury to sight. Have your blood pressure checked. If you take medicine ask your pharmacist if "scleral bleed" can be a side effect of any of the meds. If becomes recurrent see an opthamologist; not an optometrist.

Bleed: This is a sub-conjunctival hemorrhage. As long as the vision is unchanged and there is no pain, everything should be fine. If it is a little irritated, then you can use an artificial tear up to 4 times a day to lubricate. This is due to a blood vessel leaking blood and is usually without cause. Sometimes straining or blood thinner can cause this. If it continues to happen, follow up with eye md.