Blockage of a retinal artery by a thrombus (blood clot) typically affects only one eye, causing sudden blindness or loss of part of the visual field.
It requires urgent treatment, which may include eye massage, draining fluid from the eye, or medication; even with treatment, loss of vision is usually permanent.
Blockage of a retinal vein also usually affects only one eye and tends to cause deterioration of vision over several days, although sometimes visual loss may occur suddenly.
Treatment may involve medication injected into the eye or laser surgery.
Even with treatment, there is likely to be some permanent loss of vision.

Othere related diseases

CATARACT
A cataract is cloudiness of the lens in the eye, causing blurred vision. Typically, cataracts affect both eyes, but usually one eye is more severely affected. I...

CHALAZION
A chalazion is a round, red, usually painful swelling in the upper or lower eyelid caused by blockage of one of the meibomian glands (oil-secreting glands that ...

CONJUNCTIVITIS
Conjunctivitis is inflammation of the conjunctiva (the clear membrane covering the white of the eye), causing redness— hence its common name “red eye”— ...

EARWAX
Also called cerumen, earwax is produced by glands in the outer ear canal to clean and moisten the canal. Normally, the wax emerges naturally, but sometimes it b...

ECTROPION AND ENTROPION
Ectropion is a turning outward of the lower eyelid. The eyelid’s exposed inner surface becomes dry and sore, and the eye may water continuously. Because the e...

EUSTACHIAN TUBE DYSFUNCTION
The Eustachian tube, running from the middle ear to the back of the nose, acts as a drainage tube and also regulates pressure in the middle ear. In Eustachian t...

FOCUSING PROBLEMS
Farsightedness Nearsightedness Astigmatism Focusing an image sharply on the retina (the light-sensitive layer at the back of the eye) depends mainly on the len...

GLAUCOMA
Normally, fluid is continually secreted into the front of the eye by a structure called the ciliary body to nourish the tissues and maintain the shape of the ey...