A retinal tear is a small rip in the retinal tissue that leaves the retina less securely attached to the back of the eye than it ought to be. Retinal detachment occurs when the retinal tissue fully disconnects from the back of the eye. A retinal tear is usually a precursor to retinal detachment. Since retinal detachment can lead to irreversible vision loss, it is wise to treat a retinal tear before it leads to detachment.