Eye Floaters, Spots, and Flashes: Overview

Eye floaters are spots you see in your field of vision. They are common and usually harmless. 

Some spots can move around, while other floaters appear stationary. Other people may see flashes of light instead of spots, which can look like someone is turning the light switch on and off. These symptoms occur from changes in the vitreous.

The vitreous is a clear, gel-like substance that fills a large portion of your eyeball between the lens and the retina. Collagen fibers, a type of protein, allow the vitreous to attach to other structures inside your eye, including the retina, optic nerve, blood vessels, and macula. 

The vitreous contains 99 percent water, along with a small percentage of collagen and hyaluronic acid.

Functions of the vitreous include:

• Maintaining the round shape of the eyeball
• Providing structural support to the retina, which is the tissue lining the back of the eye
• Allowing light to pass through to the retina
• Providing shock absorption from trauma
• Distributing nutrients and oxygen in the eye

Common Symptoms

Eye floaters can take on many forms. Some of these different shapes include:

• Cobwebs
• Dots, which can be black, grey, or translucent
• Worm-like strands
• Ring or partial ring
• Shadow in the vision
• Blurry spot in the vision

You may notice the floaters more when looking at a white background or a blue sky. Most people find floaters annoying, but they rarely interfere with vision, unless the floater is large or dense.

Some people also see light flashes if the vitreous tugs on the retina. This symptom often occurs when the vitreous first starts to loosen and detach itself, which may or not cause further complications.

Risk Factors and Complications

Although floaters are common, some people are more likely to get them. Some risk factors are:

• Myopia (nearsightedness). Nearsighted people typically have longer eyeballs. This elongation puts stress on your retina as the tissue becomes stretched out and thinned. This stretching can also cause the vitreous attachments to loosen, increasing the risk for floaters.
• Age. Because the vitreous naturally liquefies and shrinks with age, older people are more likely to experience floaters.
• Cataract surgery. A cataract forms in the lens of your eye, which sits adjacent to your vitreous. Cataract surgery can disrupt your vitreous and retina. The ultrasound waves used to break up the cataract during surgery increases your chances of floaters.
• Trauma. Eye or head trauma can also disrupt your vitreous. Symptoms of floaters may not present immediately after the injury but can happen much later.
• Diabetes. Diabetic patients are at higher risk for vitreous and retinal complications. Diabetic retinopathy is a condition that causes blood vessels to leak and irregular blood vessels to grow in your retina.

Floaters are typically harmless. However, they can also be a sign of vision-threatening complications. These are some eye conditions associated with floaters:

• Posterior vitreous detachment (PVD). This common condition occurs when the back portion of the vitreous detaches completely from the retina. Most posterior vitreous detachments do not cause any problems. However, if the vitreous only detaches partially, the vitreous can still pull on the retina, increasing the risk for vitreous hemorrhage, retinal tear, or retinal detachment. 
• Retinal holes or tears. If the vitreous pulls on the retina with enough tension, a retinal hole or tear can occur. Nearsighted people are more prone to these problems since they have thinner retinas. Depending on the size of the hole or tear, your eye doctor can determine if treatment is necessary. 
• Retinal detachment. If fluid seeps into a retinal hole or tear, the fluid can start to build up underneath the retina, causing the tissue to detach. A retinal detachment requires immediate medical attention, as this is a vision-threatening condition. The sooner a retinal detachment is repaired, the better the prognosis.
• Vitreous hemorrhage. Several conditions can cause blood to leak into your vitreous. Some of these include diabetic retinopathy, retinal tears, posterior vitreous detachments, and hypertensive (high blood pressure-related) retinopathy. Patients with a vitreous hemorrhage may report floaters and often see blurry or red spots in their vision.
• Migraines. Migraine symptoms are often confused with eye floater symptoms. While migraines do not cause floaters, some people notice light flashes or see spots in their vision when a migraine occurs. These visual symptoms can also occur without a headache. This condition is called an ocular migraine.

If you have symptoms of light flashes, a sudden increase in floaters, shadows in your vision, or a curtain over your vision, see your eye doctor right away. These can be signs of a retinal tear or detachment.

Treatment Options

If your floaters are very bothersome, there are treatment options available to get rid of your floaters. In general, most eye doctors recommend not treating floaters unless they significantly interfere with your vision.

Laser vitreolysis is a less invasive way to remove floaters. During the procedure, the eye surgeon:

1. Instills numbing drops into your eye.
2. Places a special magnifying contact lens onto your eye.
3. Targets a laser to dissolve your floaters. 

Here are some things to consider with the laser vitreolysis procedure:

• This procedure is best for patients who have trouble with their floaters for about six months or longer. If your floaters are relatively new, your eye doctor may recommend you monitor them to see if they improve over the next several months.
• You should only consider a vitreolysis if the floaters interfere significantly with your daily activities, such as reading or driving. If you simply find the floaters annoying, but they do not impede your vision, it is best to leave the floaters alone.
• Most patients notice some improvement in their vision after treatment. However, some patients require multiple treatments. There is also a chance the treatment may not improve your symptoms.
• As with any medical procedure, there are potential risks. These risks include elevated eye pressure (higher risk of glaucoma), cataracts, retinal tears, and retinal detachments. 

Pars plana vitrectomy is a type of eye surgery that treats a variety of conditions in the retina or vitreous, such as retinal detachments or vitreous hemorrhages. In cases of extreme floaters, a vitrectomy can remove them from your eye.

During a vitrectomy, the eye surgeon: 

1. Administers local anesthesia to numb your eye. In some cases, they use general anesthesia for certain patients. 
2. Makes a small incision in the white part of your eye, called the sclera.
3. Inserts microsurgical tools through these incisions to remove your vitreous.
4. Replaces the vitreous with silicone oil or a gas bubble.

Here are some things to consider with the pars plana vitrectomy:

• This surgery is more invasive than a laser vitreolysis. Many eye doctors discourage having this procedure done if your floaters are not causing complications. 
• Your eye doctor may ask you to monitor your floaters for an extended period to see if they improve before considering a vitrectomy.
• Some studies demonstrate vitrectomies can be effective and safe for patients with significant floaters. 
• Risks of vitrectomy include elevated eye pressure (higher risk of glaucoma), cataracts, infection, swelling in the retina, retinal tears, and retinal detachments.