Symptoms
When a retinal detachment occurs, it usually results in sudden blindness. This can occur in the whole eye (or eyes), or just part of the eye, so it appears as if someone has pulled a curtain over part of your vision.
Quite often, a detached retina can be preceded by a sudden increase in floaters, and the appearance of flashes in your vision. However, there are other causes for these symptoms too, so there’s no need to panic if you do experience them. It is important to be checked out by an eye specialist, however, to identify whether a detached retina is the cause or not.
A detached retina does not cause any pain, but you should not delay in seeking medical help, because if left untreated, the loss of vision can often be permanent.

A retinal tear
Causes
Retinal detachment usually begins with a retinal tear, or hole in the retina. When a small hole or tear occurs, fluid from the eye can seep into the space between the retina and the back of the eye, which peels the retina away further.
When the retina is detached from the back of the eye, it cannot function. This means that when the retina is partially detached, there is a gap in the vision. But when it is fully detached, the affected eye is completely blind.
Movement of vitreous gel
The vitreous ‘gel’ within the eye tends to shrink with age, and can pull on the retina. In some cases, the vitreous gel can peel the retina away from the back of the eye, resulting in a macular hole or retinal tear. This can progress into a retinal detachment if left untreated.
Injury or trauma
Very occasionally, an injury to the eye or trauma can result in a retinal detachment.
Treatment
The sooner a detached retina is treated, the better the chance of a good outcome. If a retinal tear is detected early, they can often be ‘welded’ down again with a laser or by freezing. In the case of a retinal detachment, retinal detachment surgery is almost always necessary.