The retina is a thin, light-sensitive membrane covering the back of the eyeball and further attached to the optic nerve. As we perceive images, the retina converts these images into electrical impulses and sends them to the brain via the optic nerve. When retinal detachment occurs, the membrane layer separates from the eye wall, resulting in vision changes that can progress to blindness if not treated. According to the Foundation of the American Academy of Ophthalmologists, causes of retinal detachment can include an injury to the face or eye, glaucoma, cataracts, nearsightedness and previous personal or family history of the condition.
Spots and Floaters
A gel-like substance called vitreous is positioned in the back of the eye between the lens and retina. According to All About Vision.com, an online resource for eye care, as the retina detaches or the vitreous detaches from the retina, the gel breaks loose, causing floaters to suddenly appear in the field of vision. Floaters look like gray or black spots and specks passing over the field of vision along with eye movement. The vitreous also invades into the space created by the retinal separation, causing a partial detachment to become complete. This is why immediate medical treatment is necessary to prevent blindness.
Flashes of Light
Flickers or flashes of light are another early symptom of a detached retina. Normally, the eye receives a pattern of lights and the retina transmits the impulses to the brain for perception of a whole image. However, according to All About Vision.com, a mechanical, non-visual stimulation of the retina also sends electrical impulses to the brain to be interpreted as flashes of light. This suggests that the detached retina is physically touching or being pulled by surrounding tissue.
Curtain-like Shadow
The Foundation of the American Academy of Ophthalmologists states that another early symptom of retinal detachment is a sensation of a shadow in the peripheral field of vision, as well as a gray "curtain" expanding over central vision. This shadow or curtain-like cover occurs because detached areas of the retina do not function and partial vision loss results in the nonfunctioning area. Additionally, remaining functioning areas of vision may become blurry due to torn retinal blood vessels bleeding into the eye's vitreous which is normally clear, according to Medline Plus, a service of the National Institutes of Health.
