One of the most common reasons that patients come into my office for an urgent appointment is gray or black spots in their vision. These spots are called floaters and they can range from small black spots that look like pepper flakes or gnats to larger opacities that may resemble a mosquito or a spider web. The floaters may be accompanied by flashes of light or more ominously a loss of part of your side vision.
Most people, even as children or teenagers, will see translucent, gray, fiber-like images in their vision if they look up at a clear blue sky. What you are seeing is the gel that fills up the back 2/3rds of your eyeball, between your lens and your retina. This gel is known as the vitreous humor. When you are born the vitreous is a clear gelatinous mass composed of fine, evenly spaced fibers. As you age the vitreous begins to have subtle changes. The fine fibers began to become coarser and the gel begins to become more liquid-like. Most of the time you won’t notice these changes in your vision until you look at a solid, well-lit background like a white wall or a blue sky.
The more dramatic changes occur when the gel-like vitreous begins to become more and more liquid-like. Eventually, the vitreous gel collapses forward. This is what is known as a posterior vitreous detachment. At this point, the patient notices the sudden onset of significant new floaters in their vision. The detachment of the vitreous membrane from the retina begins in center of the retina and goes toward the periphery of the retina. It is this pulling on the retina by the detaching vitreous that causes the symptoms of flashing lights. The light flashes are a mechanical stimulation of the retinal photoreceptors. With each little movement of the eye the vitreous tugs on the retina until eventually it separates completely. Once there is no more traction the light flashes stop. The floaters remain in the eye but become much less noticeable over time. For the patients that have extremely symptomatic floaters there is a surgery that can be done to remove them. It is called a vitrectomy and is performed by a retinal surgeon. I typically advise patients to wait at least 6 months before deciding to have a vitrectomy done.
A posterior vitreous detachment is a normal part of aging and is a benign condition. The problem that can arise is that the detaching vitreous can tear the retina. A retinal tear can lead to a detached retina which is a condition that can lead to permanent vision loss if not caught and fixed in time. There is often no difference in the symptoms between a vitreous detachment with or without a retinal tear. You need to have a thorough exam of your retina by your eye doctor to determine if you need treatment or not. I recommend being seen within 48 hours of the onset of your symptoms.
A friend of our family was in North Carolina, vacationing in his motor home. He called me from the road and said he was noticing a floater and could he wait to see me when he got home in 2 weeks. Now the odds were that he would be fine. However, I advised him to go ahead and see an eye doctor up there. It turned out that he had a retinal detachment and had emergency surgery to repair it. That doctor saved his eyesight. The moral of the story is if you have new floaters in your vision to please have your eyes checked to avoid any permanent damage to your vision.