Please tell me what does high eye pressure mean?

Glaucoma: Intraocular pressure, iop. Normal is between 10-21. This is an indicator of the relative pressure in the eye. Fluid is formed behind the lens and flows into channels in the front of the eye. Elevated pressure can indicate glaucoma, that can cause vision loss by damage to the optic nerve. It is typically painless. Low pressure can indicate the eye is very sick, from inflammation or scarring.

Eye Pressure changes: With respiration, position, time of day etc. Consistently high eye pressures are associated with glaucoma, a disease of the optic nerve causing loss of peripheral vision. Untreated, some patients with high iop lose vision permanently. Fortunately, this usually takes a while. Eye exam(s) with visual field, oct, and photos can help resolve the diagnosis. Medication usually is effective.