Diseases & Condition--Eye Tiredness (Eye Strain)
What is Eye Strain?
Eye strain is generally defined as a condition where strain is put on
the muscles that control the eye. This type of strain can be caused by a
variety of things, but most commonly is associated with reading,
computer use, and other activities that involve peering at small items.
Sewing and craft work are also commonly associated with eye strain. A
certain amount of eye muscle strain
is considered normal, and often causes no permanent damage to sight,
but repeated overuse of eye muscles can cause damage that could lead to
surgery or the need to use glasses to improve vision.Eyestrain is a common condition that occurs when your eyes get tired from intense use, such as while driving long distances or staring at computer screens and other digital devices.
Eyestrain can be annoying. But it usually isn't serious and goes away once you rest your eyes or take other steps to reduce your eye discomfort. In some cases, signs and symptoms of eyestrain can indicate an underlying eye condition that needs treatment.
Diseases & Condition--Eye Focusing (Convergence inefficiency)
Convergence insufficiency occurs when your eyes don't work together while you're trying to focus on a nearby object. When you read or look at a close object, your eyes need to turn inward together (converge) to focus. This gives you binocular vision, enabling you to see a single image.
Convergence insufficiency can cause difficulty with reading. This may make parents or teachers suspect that a child has a learning disability, instead of an eye disorder.
Treatments for convergence insufficiency are usually effective.
Symptoms
Not everyone with convergence insufficiency experiences symptoms. Signs and symptoms occur while you're reading or doing other close work and may include:
- Eyestrain
- Headaches
- Difficulty reading — words blur or seem to move on the page
- Double vision
- Difficulty concentrating
- Squinting or closing one eye
Causes
Convergence insufficiency results from misalignment of the eyes when focusing on nearby objects. The exact cause isn't known, but the misalignment involves the muscles that move the eye. Typically, one eye drifts outward when you're focusing on a nearby word or object.
Treatments and drugs
Treatment options for convergence insufficiency include:
- Pencil pushups. In this simple exercise, you focus on a small letter on the side of a pencil as you move it closer to the bridge of your nose, stopping the movement if you have double vision. Your doctor may suggest you do this at home for 15 minutes a day, five or more days a week.
- Office or home-based vision therapy. You can do eye-focusing exercises to improve convergence. If you do this at home on a computer, you can print your results to share with your eye doctor.
- Combined therapy. Many experts recommend using vision therapy — often with computer software programs — along with pencil pushups. The combined approach may be more effective. And the computer-assisted therapy may be more engaging for children.
- Reading glasses. If computer therapy or exercises don't help, your doctor may suggest you use glasses with built-in prisms for reading. This is usually more effective for children.
- Continued observation. It's possible to receive a diagnosis of convergence insufficiency but not show any signs or symptoms. If this is true for you, watch for symptoms when you're reading or doing close work. Your doctor may want to retest you sometime in the future.
- Surgery. In rare cases, if exercises or computer-assisted therapy doesn't work, your doctor may recommend surgery.
Studies show that vision therapy at a doctor's office is more effective than doing eye exercises or computer-assisted therapy at home. Other aspects to consider before choosing a treatment are cost and convenience.
You will likely see improvement in your symptoms after four weeks of doing exercises or computer-assisted therapy. Treatment can offer long-standing relief of the symptoms of convergence insufficiency. But symptoms may come back:
- After an illness
- If you don't get enough sleep
- When you're doing a lot of reading or other close work
Another round of treatment will usually help.
Diseases & Condition--Spots in Vision (Eye Floaters)
Eye floaters are spots in your vision. They may look to you like black or gray specks, strings or cobwebs that drift about when you move your eyes and appear to dart away when you try to look at them directly.
Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid. Microscopic fibers within the vitreous tend to clump and can cast tiny shadows on your retina, which appear to you as floaters.
If you notice a sudden increase in eye floaters, contact an eye specialist immediately — especially if you also see light flashes or lose your peripheral vision. These can be symptoms of an emergency that requires prompt attention.
Symptoms
Causes
Eye floaters may be caused by:
- Age-related eye changes.Eye floaters most commonly occur as a result of age-related changes in the vitreous, the jelly-like substance that fills your eyeballs and helps maintain their round shape. Over time, the vitreous partially liquefies — a process that causes it to pull away from the eyeball's interior surface. As the vitreous shrinks and sags, it clumps and gets stringy. Bits of this debris block some of the light passing through the eye, casting tiny shadows on your retina.
- Inflammation in the back of the eye. Posterior uveitis is inflammation in the layers of the uvea in the back of the eye. Posterior uveitis, which can cause eye floaters, may be caused by infection or inflammatory diseases, among other causes.
- Bleeding in the eye. Bleeding into the vitreous can have many causes, including injury and blood vessel problems.
- Torn retina. Retinal tears can occur when a sagging vitreous tugs on the retina with enough force to tear it. Without treatment, retinal tear may lead to retinal detachment — an accumulation of fluid behind the retina that causes it to separate from the back of your eye. Untreated retinal detachment can cause permanent vision loss.
Treatments and drugs
Most eye floaters don't require treatment
Eye floaters can be frustrating, and adjusting to them can take time. However, you may eventually be able to ignore them or notice them less often.
Treatments for floaters that impair your vision
If your eye floaters impair your vision, which happens rarely, you and your eye doctor may consider treatment.
Options may include:
- Using a laser to disrupt the floaters. An ophthalmologist aims a special laser at the floaters in the vitreous, which may break them up and make them less noticeable. Some people who have this treatment report improved vision; others notice little or no difference.Risks of laser therapy include damage to your retina if the laser is aimed incorrectly. Laser surgery to treat floaters is used infrequently.
- Using surgery to remove the vitreous. An ophthalmologist removes the vitreous through a small incision and replaces it with a solution to help your eye maintain its shape. Surgery may not remove all the floaters, and new floaters can develop after surgery. Risks of vitrectomy include bleeding and retinal tears.
