Diplopia Definition - Double Vision Double Vision By Troy Bedinghaus, OD Updated April 10, 2016 Are you seeing double? Double vision is the simultaneous perception of two images of a single object. The images may be displaced horizontally, vertically, diagonally, or rotationally in relation to each other. What is double vision? Double vision usually occurs when the eyes are misaligned, or not pointed at the same object, causing us to see two different images. Both images are sent to the brain which we process as double vision. Most of the time, both of our eyes are pointed at the same object. This produces a clear, single image with just enough difference between the two images to give us a slightly different line of sight. This subtle difference gives us depth perception , often referred to as stereo vision. In fact, the farther apart an animals eyes are, the better depth perception it has. Double vision can cause problems in life, including great difficulty in completing simple tasks. Luckily, the brain naturally guards against double vision by suppressing, or ignoring, one of the two images. We have a complex set of eye muscles and nerves that communicate with each other to keep both eyes moving along together.

Causes of Double Vision The medical term for double vision is diplopia. Diplopia can be intermittent or constant. Because the pathway for the three main nerves that control eye muscle movement is long, complex and originates in the brain, double vision can be a sign of a serious neurological problem. A defect anywhere along these pathways can possibly cause double vision. Some defects are caused by an injury to the head, stroke, aneurysm, brain tumor or brain swelling. Diabetes, hypertension and multiple sclerosis are common diseases that can cause a temporary paralysis of the nerves that control the eye muscles, which may cause double vision. Another cause of double vision is strabismus . Strabismus is a condition that causes the eyes to be misaligned, often referred to as an "eye turn." Most people with strabismus are born with it and have an eye that tends to move inward or outward. Strabismus can also cause one eye to be pointed up or down. In many infants, it is difficult to find a true cause. Sometimes strabismus is caused by a large refractive error (need for prescription glasses) and sometimes eye tumors.

Most young children do not suffer from double vision even though their eyes are misaligned. Our brain often compensates and prevents us from seeing double by suppressing one of the images and making it disappear. Our brain learns to ignore the extra image, known as suppression. Children seem to adapt quickly and their brains suppress one of the images quickly. However, when one image is suppressed, a child is at risk for developing amblyopia, often referred to as lazy eye, because the eye is not being used properly. When strabismus develops in adults, double vision is more likely to occur. An adult brain has difficulty suppression one image at first because for a large part of their life, both eyes were functioning to their fullest potential. Monocular Diplopia For the most part, you must have two fully functioning eyes to experience double vision. However, there is one type of double vision that can occur in one eye, called monocular diplopia. The most common cause of monocular diplopia is a cataract . A cataract is a clouding and opacification of the normally, clear lens inside the human eye. Most cataracts develop as we age. Some cataracts can be caused by trauma to the eye.

Occasionally, the clouding occurs in sharp junctions in the lens which causes light to split into two when it enters the eyes. Some individuals perceive that as double vision. Astigmatism can also cause double vision out of one eye. Astigmatism , a common vision problem that distorts vision, can sometimes elongate or stretch out an image so much that it appears to be double. Treatment of Double Vision Cover It - The simplest form of treatment of double vision is to cover one eye with a patch. This quickly eliminates one image but has the negative side effect of decreasing your dimensional vision or depth perception. Fresnel “Press-on” Prism - Another useful way of treating double vision is to apply a Fresnel prism on top of your eyeglasses. Fresnel prism is a thin sheet of many little prisms that shift light in a certain direction. The prism moves the image that the misaligned eye is seeing into a position so that both eyes can fuse the image into a single, clear image. Fresnel prism has the advantage of being temporary. The fresnel prism can be peeled off of the glasses easily as the diplopia resolves itself. Fresnel prism is useful when double vision is caused by conditions such as diabetes or hypertension.

Most often, the double vision lasts less than 6-9 months and then goes away when the underlying systemic condition is being treated. Ophthalmic Prism - If double vision is more permanent, then regular, ophthalmic prism can be ground into your eyeglass prescription. It occasionally increases the thickness of the lens on one side but is better looking cosmetically than a Fresnel prism. Vision Therapy - Vision Therapy (VT) encompasses a lot of different techniques to correct double vision and strabismus. Sometimes certain machines and computer models are used to give the person behavioral feedback to control the double vision. Other times, specific eye muscle exercises are done to strengthen the eye muscles. Surgery - Surgery for double vision is very successful in most cases. Eye surgeons who specialize in eye muscle surgery use a variety of techniques that involve shortening or moving eye muscles. Adjustable sutures are used to fine tune the eye muscle correction directly after surgery. Botox - Botulinum toxin is injected directly into one of the muscles controlling eye movement. This temporarily blocks the nerve impulse and causes the muscle to be paralyzed. This muscle relaxes and the other eye muscles take up the slack to straighten the eye.

Side effects including a droopy eyelid or worsened double vision. What You Should Know Double vision is a serious health concern. However “sudden onset” double vision is of special concern. When diplopia comes on suddenly, a neurological problem in your brain should always be ruled out before investigating more common causes. If you are experiencing double vision, you should be evaluated by an optometrist, ophthalmologist , neurologist or other medical professional immediately. Upon evaluation, your doctor will ask you the following questions: Did the double vision appear suddenly, or has it been there for some time? Is it constant, or does it seem to come and go? Does the double vision go away when you cover one eye? Do you see double out of one eye, or both eyes? Source: Neuro-Ophthalmology - Textbook of Ophthalmology. Slamovits, Thomas L. and Ronald Burd. Copyright 1994, Mosby-Year Book Europe, Ltd. Continue Reading Double Vision: Check Your Symptoms and Signs Headache Double vision , or "seeing double," occurs when two nonmatching images are sent to the part of the brain that is responsible for processing visual input.

If this occurs over the long term, the brain will eventually compensate for the two signals by suppressing one signal, so that a single image is perceived. The suppressed eye may eventually become amblyopic (" lazy eye ") with resultant vision loss . Double vision can result from impairment in any part of the vision system, including the cornea , eye muscles, lens , nerves, or the brain. The most common cause of diplopia is misalignment of the two eyes that can arise from several different conditions. Some diseases such as myasthenia gravis and Grave's disease can cause weakness of the eye muscles, leading to misalignment of the eyes and double vision. Poorly controlled diabetes can ultimately result in nerve damage that can manifest as diplopia, and diplopia can arise as a result of stroke , head injury , or other brain damage . While diplopia can be a symptom of the conditions listed below, it is not always present in these conditions. Medically Reviewed by a Doctor on 3/6/2012 Health concern on your mind? Visit the Symptom Checker. REFERENCE: Fauci, Anthony S., et al. Harrison's Principles of Internal Medicine. 17th ed.

United States: McGraw-Hill Professional, 2008. Main Article on Double Vision Double Vision Double vision (diplopia) is a symptom that my indicate Graves' disease, myasthenia gravis, stroke, multiple sclerosis,... learn more » Causes of Double Vision Alcoholism Alcoholism is a disease that includes alcohol craving and continued drinking despite repeated alcohol-related problems, such as... learn more » In This Article Vision Care Glossary | Definitions of Eye Care and Vision Terms A-B Glossary of Eye Care Terms - A-B Like This Page? Please Share! A-B | C-D | E-H | I-L | M-O | P | Q-S | T-Z Abbe value A measure of the tendency of an eyeglass lens material to cause chromatic aberration, which is an optical distortion that causes colored halos or fringes around lights or blurred vision, especially when looking through the periphery of the lens. The lower the Abbe number, the more likely chromatic aberration will be noticeable. aberrometer A device that can identify common and more obscure vision errors by measuring the way light waves travel through the eye's optical system. ablation Removal.

In vision, ablation refers to the surgical removal of eye tissue to correct a refractive error such as myopia . For example, in laser procedures such as LASIK and PRK , the excimer laser ablates, or removes, tissue from the cornea. accommodation Eye's ability to automatically change focus from seeing at one distance to seeing at another. accommodation disorder Accommodation refers to the eye's ability to automatically change focus from seeing at a distance to seeing at near. Accommodation disorders have a variety of causes. Symptoms include blurred vision, double vision, eye strain, headache, fatigue and difficulty concentrating (particularly while reading). Presbyopia is an accommodation disorder that affects everyone if they become old enough, since its causes relate to the aging of the eyes. acetate Type of plastic often used in eyeglass frames . acrodermatitis enteropathica Rare inherited condition characterized by dermatitis, hair loss, diarrhea and zinc deficiency. The most common eye symptom is light sensitivity , but conjunctivitis and other symptoms may also be present. AK (astigmatic keratotomy) Procedure in which a surgeon cuts the cornea so that it is more spherical when it heals, thus reducing astigmatism.

albinism Condition where a person or animal lacks pigment. Albinos' eyes often have very light blue or pink irises and a pink pupil (due to lack of pigment inside the back of the eye). Visual symptoms include light sensitivity , nystagmus , blurred vision, vision loss and strabismus . allergen Any substance (such as pollen, mold, dust or animal dander) that causes allergy symptoms in sensitive individuals. allergy Reaction of the body's immune system to a foreign substance (e.g., pollen, animal dander, etc.). When the eyes are affected, the most common symptoms are redness, itching, chemosis, tearing, swollen eyelids and stickiness. Read more about allergies and the eyes. ALS (Lou Gehrig's disease) Amyotrophic lateral sclerosis is a disease that causes degeneration of neurons in the brain stem and spinal cord. Voluntary muscles atrophy and eventually become paralyzed.

Recommended For You Learn how Optometry Giving Sight helps 670 million people to see again amaurosis fugax Sudden and usually temporary vision loss caused by an " eye stroke ." When a clot or blockage disrupts blood flow to the eye, symptoms can include curtain-like darkness, usually in just one eye. amblyopia Also called lazy eye. Undeveloped central vision in one eye that leads to the use of the other eye as the dominant eye . Strabismus is the leading cause, followed by anisometropia. There are no symptoms. The patient may be found squinting and closing one eye to see; there may be unrecognized blurred vision in one eye and vision loss. Read more about amblyopia (lazy eye). AMD or ARMD (age-related macular degeneration) Disorder characterized by the gradual loss of central vision due to a damaged macula (which is made up of retinal cones necessary for sight). Read more about macular degeneration. angiogenesis The formation of new blood vessels in the body. Also see neovascularization . aniridia Absent or partially absent iris, typically congenital. Additional symptoms include poor vision and photophobia. anisocoria Unequal pupil size.

Causes include glaucoma , head or eye trauma , an intracranial tumor, infection of the membranes surrounding the brain and previous intraocular surgery. A small percent of the population has unequal-sized pupils naturally (without any known cause). anisometropia Condition where the eyes have a significantly different refractive power from each other, so the prescription required for good vision will be different for each eye. anophthalmos Absence of one or both eyes. Anophthalmos may be congenital or due to trauma, infection or other causes. Symptoms include reduced depth perception and peripheral vision . You May Also Like What's the most popular eye color ever? ANSI The American National Standards Institute is a private, non-profit organization that coordinates efforts to develop standards for manufacturing many different products, including eyeglass lenses . For example, certain ANSI standards define acceptable levels of impact resistance for safety eyewear. ANSI Z87.1-2003 Standard The American National Standards Institute's Practice for Occupational and Educational Eye and Face Protection; eyewear that meets this standard is considered safer than eyewear that does not. anterior chamber Part of the eye behind the cornea and in front of the iris and lens.

antibody A protein activated by the body's immune system that fights infection, toxins and other foreign substances. antioxidant Substance that inhibits oxidation and can guard the body from damaging effects of free radicals. Molecules with one or more unpaired electrons, free radicals can destroy cells and play a role in many diseases. Antioxidant vitamins include B, C and beta-carotene. Antioxidants may help prevent macular degeneration and other eye diseases ; many studies are in progress. More about nutrition and the eyes. anti-reflective coating (AR coating) Thin layer(s) applied to a lens to reduce the amount of reflected light and glare that reaches the eye. Read more about anti-reflective lenses and other eyeglass lens coatings . apheresis A process in which blood is drawn outside the body, certain compounds are removed, and the blood is returned to the body. The technique has various applications, including: harvesting of needed components such as plasma or white blood cells; and removing harmful components such as large proteins, in order to treat the dry form of age-related macular degeneration (AMD). aqueous humor The clear, watery fluid that fills the space between the cornea and lens of the eye .

The aqueous humor (or aqueous) is produced by the ciliary body behind the iris and drains from the anterior chamber of the eye through the trabecular meshwork . Failure of the aqueous humor to drain properly from the eye increases intraocular pressure (IOP) and can lead to glaucoma . Argyll Robertson pupil Small, irregular pupil, usually caused by syphilis. Argyll Robertson pupils do not respond to light. aspheric Not quite spherical. Aspheric eyeglass lenses are popular among people who have strong prescriptions because they are thin and lightweight, and reduce distortion and eye magnification. Aspheric contact lenses can work as a multifocal, or to correct a single-vision problem like astigmatism. asteroid hyalosis A benign condition that creates suspended particles within the eye's interior, observable by an eye doctor during an exam. Floaters are not usually associated. These yellowish particles made of fats ( lipids ) rarely interfere with vision or cause symptoms. The particles move within the eye's gel-like vitreous and resemble stars at night. The condition is not well understood, but appears associated with aging.

astigmatism A refractive error where objects at all distances have a distorted appearance ("streaked" or stretched, with elongated shapes and unequally blurred borders). Symptoms of astigmatism include squinting, eye strain, headaches and reading problems. Read more about astigmatism. atopy Type of allergy where levels of the antibody immunoglobin E are increased; atopy includes rhinitis, asthma, hay fever and eczema. aura A sensation experienced before an attack of epileptic seizure, migraine or other disorder. Examples are flashes of light, colored lights, numbness, coldness and even hearing voices. aviator glasses Glasses with a large, upside-down teardrop shape like the sunglasses that aircraft pilots have worn traditionally; they usually have a metal frame and large, tinted lenses, but they are also available with plastic frames and clear lenses. Often they have a double-bar bridge. They offer a distinctly retro or vintage look. band keratopathy Opacity of the corneal stroma and Bowman's membrane. Symptoms include vision loss and foreign body sensation. base curve The main or steepest part of the curve used in the design of a contact lens.

Measured in millimeters, the base curve is prescribed to match or complement the curvature of your cornea. The lower the number, the steeper the curve of your cornea. Bell's palsy See cranial nerve palsy . benign essential blepharospasm Neurological disorder causing involuntary muscle contractions, with eyelid muscle spasms. best corrected visual acuity (BCVA) The best vision you can achieve with correction (such as glasses), as measured on the standard Snellen eye chart . For example, if your uncorrected eyesight is 20/200, but you can see 20/20 with glasses, your BCVA is 20/20. beta blocker Drug that widens or dilates blood vessels, thus enabling more normal flow of blood. Topical beta blockers applied as eye drops also can lessen fluid production and lower internal eye pressure ( intraocular pressure ) in eye diseases such as glaucoma to reduce the possibility of optic nerve damage. Beta blockers also are used to control high blood pressure (hypertension). Side effects can include respiratory problems. beta titanium Titanium alloy. Beta-titanium eyeglass frames are both strong and flexible.

bifocal Lens with one segment for near vision and one segment for far vision. The term " bifocal " can apply to both eyeglass lenses and contact lenses . binocular vision Ability of both eyes to work together to achieve proper focus, depth perception and range of vision. biocompatible Able to coexist with living tissues without harming them. For example, artificial lenses are designed to be biocompatible with tissue inside the eye so they won't cause a toxic or immunilogical response that would harm the eye. bioptic telescopic lenses (BTL) Devices attached to glasses that provide extreme magnification, typically used for driving. For people with low vision who are qualified, telescopic lenses are attached above the driver's line of sight to help magnify objects such as road signs. blepharitis Inflammation of the eyelid(s), typically around the eyelashes. Various types of dermatitis, rosacea and allergic reactions can cause blepharitis. Symptoms include a red or pink eyelid, crusty lid or lashes, burning, foreign body sensation, eye or eyelid pain or discomfort, dry eyelid, dry eye, eyelash loss, grittiness, stickiness, eyelid swelling and tearing.

Read more about blepharitis. blepharochalasis Excessive, drooping eyelid skin caused by recurring swelling. Blepharochalasis typically occurs in young people. blepharoconjunctivitis Inflammation of the eyelid and conjunctiva. Infections and allergic reactions are among the causes. Symptoms include a red or pink eye, a red or pink eyelid, pain or discomfort of the eye or around the eye, tearing, burning, eye dryness and eye stickiness. blepharospasm Involuntary increased blinking that progresses to spasms in both eyes. The exact cause is unknown, but doctors believe it to be a central nervous system disorder. It can produce a functional blindness since the patient can't open his or her eyes long enough to function visually. blue light Found in the light spectrum next to violet, which has the shortest wavelength of visible light. Also known as High Energy Visible (HEV) light, blue light has been linked to eye damage and diseases such as age-related macular degeneration . Read more about blue light. botulism Serious illness from a toxin produced by Clostridium bacteria (usually Clostridium botulinum).

Infant botulism and food-borne botulism are the most common forms in the United States. Symptoms include double vision , blurred vision, drooping eyelids (ptosis) , muscle weakness, difficulty speaking, difficulty swallowing, difficulty breathing and nausea. Bowman's membrane Corneal layer between the epithelium and the stroma. bridge The part of an eyeglass frame that extends across the nose. Double Vision (Diplopia) Guide: Causes, Symptoms and Treatment Options Double Vision (Diplopia) What Is It? Double vision, also called diplopia, causes a person to see two images of a single object. There are two types of double vision: monocular and binocular. Monocular diplopia is double vision in only one eye. The double vision continues even when the other eye is covered. The doubling does not go away when you look in different directions. Monocular diplopia can be caused by: Astigmatism — This is an abnormal curvature of the front surface of the cornea. Keratoconus — The cornea gradually becomes thin and cone-shaped.

Pterygium — This is a thickening of the conjunctiva, the thin mucous membrane that lines the inner surface of the eyelids and the whites of the eyes. The thickening extends on the cornea, the clear part of the surface of the eye. Cataracts — The lens gradually becomes less transparent. Risk factors include being older than 65, having eye trauma or long-term diabetes, smoking, using steroid medications or having radiation treatments. A dislocated lens — The ligaments that hold the lens in place are broken, and the lens moves out of place or wiggles. This can be caused by trauma to the eye or a condition known as Marfan's syndrome. A mass or swelling in the eyelid — This condition can press on the front of the eye. Dry eye — Your eyes do not produce enough tears. Some retinal problems — Double vision can happen when the surface of the retina is not perfectly smooth, which can have a variety of causes. Binocular diplopia is double vision related to a misalignment of the eyes. The double vision stops if either eye is covered.

Any problem that affects one or more of the muscles around the eyeball that control the direction of the gaze can cause binocular diplopia. These are called extraocular muscles. Such problems include: Strabismus — This is a childhood misalignment of the eyes that affects about 4% of children younger than age 6. Damage to nerves controlling the extraocular muscles — Nerves can be injured by brain damage caused by infection, multiple sclerosis, stroke, head trauma or a brain tumor, especially a tumor located at the lower back portion of the brain. A tumor growing inside the eye socket or trauma to the eye socket can damage a nerve anywhere along its route to the eye muscles. Diabetes — This disease can lead to problems with the nerves that control eye muscle movements. Sometimes this can happen before the person is aware that he or she has diabetes. Myasthenia gravis — This is a neuromuscular illness that causes the body's muscles to tire easily and become weak. It occurs because the body's immune system mistakenly attacks the places where nerves transmit impulses to muscles, telling the muscles to contract. Graves' disease — This is the most common cause of an overactive thyroid (hyperthyroidism).

Some people with Graves' disease develop double vision due to swelling and thickening of the muscles that move the eyes within the eye socket. Trauma to the eye muscles — The muscles of the eye socket can be injured by facial trauma, especially by a fracture of the thin bones of the eye socket. Symptoms The only symptom is seeing two images of a single object. Diagnosis The first step is to determine whether your double vision is monocular or binocular. To do this, your doctor will ask you to cover one eye and then the other. If you have monocular diplopia, your doctor will evaluate you for conditions, such as cataracts, that could be causing the problem. You will then need to see an eye specialist (an ophthalmologist). If the problem is binocular and there has been no facial trauma, then your doctor will want to know if you have diabetes, Graves' disease or neurological disorders. In diagnosing binocular diplopia, your doctor has to determine which eye muscles are affected. To do this, you will be asked to look at the doctor's finger as he moves it up, down, left and right. This lets the doctor see how far your eye can move in each direction.

Your doctor also will cover one eye and then the other, while you focus on a target. If the doctor sees your eyes shift as the eye cover is moved, it means your eyes are not aligned properly. Prisms may be placed over your eye to shift the image, and the test is repeated. The prisms allow the doctor to measure the amount or degree of your double vision when you look in different directions. This helps to diagnose the problem and monitor the problem over time. Your doctor will use the results of this exam, together with your medical history and additional symptoms, to determine if you need more tests. For example, if your doctor suspects that you have hyperthyroidism, then you will need blood tests to measure thyroid hormone levels. If your doctor suspects that something is affecting the nerves to your eye muscles, you may need a magnetic resonance imaging (MRI) or computed tomography (CT) scan of your head to check for signs of trauma, bleeding, tumor or blood vessel malformations in the brain. In most cases, double vision is easy to pinpoint in adults, because they can describe what they are seeing. Symptoms are tougher to pinpoint in children, who may not be able to explain what is wrong.

Parents may notice that the child is squinting, covering one eye with a hand, tilting or turning the head abnormally, or looking sideways. Expected Duration How long your double vision lasts depends on what is causing it. For example, cataracts and pterygium may become worse over time, but both can be corrected immediately with surgery. In people whose double vision is caused by diabetes, the nerve often regrows after several months. When this happens, double vision gradually disappears. Children with double vision caused by strabismus can improve with treatment. Prevention Some causes of double vision can be prevented. To help prevent double vision related to head trauma, wear a seat belt with a shoulder harness while driving, and wear protective goggles and headgear during sporting activities and at work, if your work carries a high risk of eye injury. People with diabetes can decrease their chance of nerve damage, which can lead to double vision, by controlling blood sugar. There is no way to prevent age-related cataracts or some other forms of double vision. Treatment Treating double vision depends on its cause. For example, people with astigmatism that causes double vision can wear special contact lenses. Sometimes, simply updating your prescription eyeglasses takes care of the problem.

Surgery is used to treat cataracts and pterygium, and surgery on the eye muscles can treat certain types of double vision. Often, adjustable stitches are used so that the position of the eyes can be fine-tuned a few hours after the surgery. That way, the patient is alert for the adjustment and can report whether the double vision is gone. Prisms also may be used in the glasses to fine-tune the surgery by moving the image seen with one eye to coincide with the other eye. For children with strabismus, treatment includes wearing prescription eyeglasses, prism vision therapy to train the eyes to align properly, or surgery. Double vision caused by a medical or neurological disease may improve by treating the disease. Eye specialists may consider other strategies to help improve the eye movements. Injections of botulinum toxin ( Botox ) can weaken strong eye muscles opposite the weakened one to help balance vision. When To Call A Professional Call your doctor right away if you have a dramatic change in vision or sudden difficulty seeing clearly. Children should have their first eye exam before they are 6 months old, with a follow-up exam at age 3.

Adults older than age 40 should have an eye examination every two years, even if they have no noticeable vision problems. Prognosis The outlook for double vision depends on its cause. For example, surgery improves the vision of more than 90% of patients with cataracts. Although surgery also can remove a pterygium, the abnormal growth can come back and eventually become larger than the original. For most children with strabismus, the prognosis is excellent if the condition is detected and treated early. Learn more about Double Vision (Diplopia) Symptom checker: Glossary of Vision Loss Terms SHOP Glossary of Vision Loss Terms The terms and definitions found in this glossary relate to vision and vision loss. Please note that this glossary is not comprehensive. 20/20 vision - A measurement of visual acuity (or clearness of sight) that most eye care professionals consider as the mean. The level of acuity is routinely measured by requiring an individual to identify various sizes of black symbols on a white background at a distance - an eye chart. The first numeral 20 defines the distance in feet from the individual.

The second numeral 20 defines the distance from which a person can distinguish characters on an eye chart that is 20 feet away. Most people can identify characters on an eye chart at 20 feet. A person with 20/200 eyesight can see at 20 feet what a person with normal sight (20/20) can see when standing 200 feet away. AMD - AMD is an acronym for Age-related Macular Degeneration, characterized by a worsening loss of central vision as a result of deterioration of the macula , which contains retinal cones that are required for sight. Learn more about AMD / Macular Degeneration Amsler Grid - A black-lined grid on a white background, used for testing central sight field distortion and impairments that signal macular degeneration and other vision loss issues. See a graphic representation of an Amsler Grid . Aqueous Humor - the clear fluid contained between the iris and cornea that provides necessary nutrients to the lens and cornea. When this fluid cannot drain, it creates unrelieved pressure that can result in Glaucoma and vision loss. Learn more about Glaucoma.

Astigmatism - An eye disorder caused by uneven curvature of the eyeball that motivates light rays to bend, targeting more than one point of the retina, instead of a single spot. This causes blurry vision, vague shadows on characters when reading, and slight double vision. Blepharospasm - A condition that causes involuntary blinking to an excessive measure that the affected individual cannot see. Blepharospasm is considered as a form of functional blindness. Braille - A tactile reading and writing system invented by Louis Braille in the 1820s and widely used by the blind and deaf-blind. Braille is made up of a system of raised dots that are felt with the fingertips. Braille makes reading, writing, note taking, and communicating possible for blind and deaf-blind users. Braille display - A tactile device consisting of a row of rectangular cells, each of which contains a series of moveable pins. The pins are controlled electronically to move up or down to form Braille characters. The characters depict the information that appears on the text source, typically via a computer or notetaker device.

Cataracts - Commonly caused by aging in conjunction with diabetes, excessive exposure to UV rays, and sometimes caused by smoking and excessive steroid use, cataracts result in clouding or yellowing of the eye lens and, thus, blurred vision; halos around objects ( in particular, lights); glare; and diminished perception of color saturation. Learn more about Cataracts. CCTV / Closed-circuit television - an older term for a video camera system that broadcasts a signal to a specific monitor (as opposed to a public broadcast source). The more common term for use for people with low vision is video magnifier . CMV Retinitis - A visual impairment characterized by spots before the eyes (floaters), blurred and/or distorted vision, commonly experienced by persons with immune deficiencies. Contrast sensitivity - A property that regulates the level at which the eye can detect differences in contrast between an object or character and its background - for instance, the contrast between a black letter on a white page. Corneal Dystrophy - Classified under several categories, corneal dystrophy is a medical syndrome that results in loss of transparency of the cornea. Individuals who have this condition experience differing levels of blurred vision, light sensitivity, and vision loss.

Diabetic Retinopathy - The leading cause of vision loss in persons who are diagnosed with diabetes. Diabetic retinopathy is brought on by leakage of the retinal blood vessels and can develop into progressive blurred vision, double vision, floaters, visual distortion and, ultimately, some degree of blindness. Learn more about Diabetic Retinopathy . Glaucoma - A sight impairment caused by unrelieved pressure inside the eye as a result of fluid build-up. Permanent impairment can range from loss of peripheral vision to severe vision loss. Individuals with glaucoma may experience increased frequency of headaches, blurred vision, halos around lights, difficulty seeing in the dark, and sometimes, a non-reactive pupil, pain, or even a swollen eye. Learn more about Glaucoma . Grave’s Disease - An autoimmune disorder present in cases of thyroid abnormality. Grave’s Disease can affect vision, including eye discomfort, double vision, and degrees of vision loss. Hyperopia / Hyperopic / Farsighted - A person is considered “farsighted,” when items at a distance are in focus, but close object are blurry. The medical term for farsightedness is hyperopia.

Keratoconus - An eye disorder that leads to degeneration of vision and various degrees of vision loss, ranging from blurred, doubled or distorted vision to severe vision loss that cannot be improved by glasses or other common optical aids. Keratoconus results from a severe form of astigmatism in which the cornea thins and reforms into a cone-shaped bulge. Legally blind - Having 20/200 vision in the best eye with correction or a visual field of 20 degrees or less. Low vision - A significant reduction of visual acuity that ordinary eyeglasses, contact lenses, and/or medical treatment cannot completely correct. Macula - The small area in the retina that contains special cells that are especially sensitive to light. The macula enables people to see fine details clearly. Strabismus and Amblyopia 201 E 65th St NY, NY 10021 Srabismus & Amblyopia What is Meant By Crossed Eyes or Lazy Eye? Strabismus , the technical term for eye turn, occurs when one of the two eyes does not aim at the spot one is looking at.

An eye may turn inwards (esotropia), outwards (exotropia), or upwards hypertropia. The eye turn may occur some of the time (intermittent) or all the time (constant). When the eyes are not aligned the following may happen: the patient sees double (usually occurring when the eye turn develops after 6 years of age); one eye is suppressed or turned off to avoid double vision; there is a loss of two-eyed depth perception (stereopsis or 3D); and/or the eyes develop abnormal binocular coordination. If one eye turns all the time or if the eyes have different eye glass prescriptions, e.g. one is mildly farsighted while the other is markly farsighted, then one eye sees clearly while the other sees blurred. The lack of clear vision in one eye will cause it to develop Amblyopia (commonly called lazy eye). To develop normal vision babies require clear images in each eye which are perfectly aligned. If one of the images is blurred (due to astigmatism and/or significant optical difference between the two eyes) or misaligned (strabismus), during the early development years, then the brain interferes with the development of normal vision.

The brain can not deal with the inequality of image. The "good" eye will inhibit the other eye causing the visual pathways not to develop normally. This semi-permanent decrease in vision is called Amblyopia . Even with glasses the amblyopic eye will not see 20/20 or normally. It is important to understand that the reduction in vision can not be corrected only by the prescription of glasses. H owever, equalization of the images is the first step in treatment, i.e. glasses. After getting new glasses for your child we should measure the visual acuity of each eye. This may be performed at our office or at your home. To test the vision in the right eye at home cover the left eye and then click here to view the interactive acuity tester . Then cover the right eye and test the vision in the left eye. For young children use the picture chart. The eye must be treated with glasses, patching, drops and exercises. (For more information about patching and obtaining patches click here ) The "lazy" eye needs to be made to work. Amblyopia develops relatively early in life (usually before the age of 2, but up to 6 or 7).

Both amblyopia and strabismus must be attended to during the early years of life. Children rarely grow out of strabismus. Amblyopia causes more permanent loss of vision in the under 40 years of age than all the combined diseases and trauma. These common conditions which affect approximately five percent of children must be detected and treated early. The earlier the diagnosis and treatment the better the results. We recommend that the first examination for your child be at 9 mos. of age. What Can We Do About Strabismus or Amblyopia? Treatment of amblyopia and strabismus may include glasses, patches, exercises and possibly even surgery. (see Testimonials ). Early treatment is clearly more effective, however, we have often been successful in treatment of both amblyopia and strabismus in later years. While surgery does have a place in treatment -- it eliminates the mechanical demand to align the eyes and makes them appear straighter -- surgery rarely makes the eyes work together normally. The best chance of developing normal or near-normal binocular vision requires vision therapy to re-educate the eyes. Both visual acuity and eye coordination can be dramatically improved with vision therapy.

Our office specializes in strabismus and amblyopia. Dr. Cooper has trained over 500 doctors in the area of strabismus. He is also on the editorial board of Binocular Vision and Eye Muscle Surgery, and has authored over 60 research articles in the area. For more information on lazy eye and strabismus, visit strabismus.org , (a detailed comprehensive WEB site written by Dr. Cooper devoted to amblyopia and strabismus), children-special-needs.org or visiontherapy.org . Concussion | definition of concussion by Medical dictionary Concussion | definition of concussion by Medical dictionary Related to concussion: Post concussion syndrome Concussion Definition Concussion is a trauma-induced change in mental status, with confusion and amnesia , and with or without a brief loss of consciousness. Description A concussion occurs when the head hits or is hit by an object, or when the brain is jarred against the skull, with sufficient force to cause temporary loss of function in the higher centers of the brain. The injured person may remain conscious or lose consciousness briefly, and is disoriented for some minutes after the blow.

According to the Centers for Disease Control and Prevention, approximately 300,000 people sustain mild to moderate sports-related brain injuries each year, most of them young men between 16 and 25. While concussion usually resolves on its own without lasting effect, it can set the stage for a much more serious condition. "Second impact syndrome" occurs when a person with a concussion, even a very mild one, suffers a second blow before fully recovering from the first. The brain swelling and increased intracranial pressure that can result is potentially fatal. More than 20 such cases have been reported since the syndrome was first described in 1984. Causes and symptoms Causes Most concussions are caused by motor vehicle accidents and sports injuries . In motor vehicle accidents, concussion can occur without an actual blow to the head. Instead, concussion occurs because the skull suddenly decelerates or stops, which causes the brain to be jarred against the skull. Contact sports, especially football, hockey, and boxing, are among those most likely to lead to concussion. Other significant causes include falls, collisions, or blows due to bicycling, horseback riding, skiing, and soccer.

The risk of concussion from football is extremely high, especially at the high school level. Studies show that approximately one in five players suffer concussion or more serious brain injury during their brief high-school careers. The rate at the collegiate level is approximately one in 20. Rates for hockey players are not known as certainly, but are believed to be similar. Concussion and lasting brain damage is an especially significant risk for boxers, since the goal of the sport is, in fact, to deliver a concussion to the opponent. For this reason, the American Academy of Neurology has called for a ban on boxing. Repeated concussions over months or years can cause cumulative head injury . The cumulative brain injuries suffered by most boxers can lead to permanent brain damage. Multiple blows to the head can cause "punch-drunk" syndrome or dementia pugilistica, as evidenced by Muhammaed Ali, whose parkinsonism is a result of his career in the ring. Young children are likely to suffer concussions from falls or collisions on the playground or around the home. Child abuse is, unfortunately, another common cause of concussion.

Symptoms disorientation as to time, date, or place confusion vacant stare or confused expression incoherent or incomprehensible speech amnesia for the events immediately preceding the blow nausea or vomiting double vision ringing in the ears These symptoms may last from several minutes to several hours. More severe or longer-lasting symptoms may indicate more severe brain injury. The person with a concussion may or may not lose consciousness from the blow; if so, it will be for several minutes at the most. More prolonged unconsciousness indicates more severe brain injury. The severity of concussion is graded on a three-point scale, used as a basis for treatment decisions. Grade 1: no loss of consciousness, transient confusion, and other symptoms that resolve within 15 minutes. Grade 2: no loss of consciousness, transient confusion, and other symptoms that require more than 15 minutes to resolve. Grade 3: loss of consciousness for any period. Days or weeks after the accident, the person may show signs of: headache The occurrence of such symptoms is called "post-concussion syndrome." Diagnosis It is very important for those attending a person with concussion to pay close attention to the person's symptoms and progression immediately after the accident.

The duration of unconsciousness and degree of confusion are very important indicators of the severity of the injury and help guide the diagnostic process and treatment decisions. A doctor, nurse, or emergency medical technician may make an immediate assessment based on the severity of the symptoms; a neurologic exam of the pupils, coordination, and sensation; and brief tests of orientation, memory, and concentration. Those with very mild concussions may not need to be hospitalized or have expensive diagnostic tests. Questionable or more severe cases may require computed tomography scan (CT) or magnetic resonance imaging (MRI) scans to look for brain injury. Treatment The symptoms of concussion usually clear quickly and without lasting effect, if no further injury is sustained during the healing process. Guidelines for returning to sports activities are based on the severity of the concussion. A grade 1 concussion can usually be treated with rest and continued observation alone. The person may return to sports activities that same day, but only after examination by a trained professional, and after all symptoms have completely resolved. If the person sustains a second concussion of any severity that same day, he or she should not be allowed to continue contact sports until he or she has been symptom-free, during both rest and activity, for one week.

A person with a grade 2 concussion must discontinue sports activity for the day, should be evaluated by a trained professional, and should be observed closely throughout the day to make sure that all symptoms have completely cleared. Worsening of symptoms, or continuation of any symptoms beyond one week, indicates the need for a CT or MRI scan. Return to contact sports should only occur after one week with no symptoms, both at rest and during activity, and following examination by a physician. Following a second grade 2 concussion, the person should remain symptom-free for two weeks before resuming contact sports. A person with a grade 3 concussion (involving any loss of consciousness, no matter how brief) should be examined by a medical professional either on the scene or in an emergency room. More severe symptoms may warrant a CT or MRI scan, along with a thorough neurological and physical exam. The person should be hospitalized if any abnormalities are found or if confusion persists. Prolonged unconsciousness and worsening symptoms require urgent neurosurgical evaluation or transfer to a trauma center. Following discharge from professional care, the patient is closely monitored for neurological symptoms which may arise or worsen.

If headaches or other symptoms worsen or last longer than one week, a CT or MRI scan should be performed. Contact sports are avoided for one week following unconsciousness of only seconds, and for two weeks for unconsciousness of a minute or more. A person receiving a second grade 3 concussion should avoid contact sports for at least a month after all symptoms have cleared, and then only with the approval of a physician. If signs of brain swelling or bleeding are seen on a CT or MRI scan, the athlete should not return to the sport for the rest of the season, or even indefinitely. For someone who has sustained a concussion of any severity, it is critically important that he or she avoid the possibility of another blow to the head until well after all symptoms have cleared to prevent second-impact syndrome. The guidelines above are designed to minimize the risk of this syndrome. Prognosis Concussion usually leaves no lasting neurological problems. Nonetheless, symptoms of post-concussion syndrome may last for weeks or even months. Studies of concussion in contact sports have shown that the risk of sustaining a second concussion is even greater than it was for the first if the person continues to engage in the sport. Prevention Many cases of concussion can be prevented by using appropriate protective equipment.

This includes seat belts and air bags in automobiles, and helmets in all contact sports. Helmets should also be worn when bicycling, skiing, or horseback riding. Soccer players should avoid heading the ball when it is kicked at high velocity from close range. Playground equipment should be underlaid with soft material, either sand or special matting. The value of high-contact sports such as boxing, football, or hockey should be weighed against the high risk of brain injury during a young person's participation in the sport. Steering a child's general enthusiasm for sports into activities less apt to produce head impacts may reduce the likelihood of brain injury. Resources Evans, R. Neurology and Trauma. W. B. Saunders Co., 1996. Organizations American Academy of Neurology. 1080 Montreal Ave., St. Paul, MN 55116. (612) 695-1940. Key terms Amnesia — A loss of memory that may be caused by brain injury, such as concussion. Parkinsonism — A neurological disorder that includes a fine tremor, muscular weakness and rigidity, and an altered way of walking.

concussion a violent jar or shock, or the condition that results from such an injury. brain concussion loss of consciousness, transient or prolonged, due to a blow to the head; breathing often is unusually rapid or slow. Outward evidence of the injury may include bleeding, sometimes from the nose, and contusions (bruises). There may be residual signs such as local paralysis on recovery. spinal cord concussion may lead to temporary paresis or spinal shock, with possible local paralysis continuing after partial recovery. concussion stunner a sharp blow to the head sufficient to cause stunning may be used as a prelude to euthanasia or, in laboratory animals, as a means of euthanasia on its own. Patient discussion about concussion Q. What is a concussion? How do you treat it? My child fell and hit his head and passed out. We went to the hospital and they say it’s a concussion and he’ll be fine. Can some one explain what it is exactly? A. When your brain gets hit hard- this is concussion.

But there’s a nice short video about it with a nice pediatrician that explains it: Eye Muscle Surgery | definition of Eye Muscle Surgery by Medical dictionary Eye Muscle Surgery | definition of Eye Muscle Surgery by Medical dictionary Definition Eye muscle surgery is surgery to weaken, strengthen, or reposition any of the muscles that move the eyeball (the extraocular muscles). Purpose The purpose of eye muscle surgery is generally to align the pair of eyes so that they gaze in the same direction and move together as a team, either to improve appearance or to aid in the development of binocular vision in a young child. To achieve binocular vision, the goal is to align the eyes so that the location of the image on the retina of one eye corresponds to the location of the image on the retina of the other eye. In addition, sometimes eye muscle surgery can help people with other eye disorders (nystagmus and Duane syndrome, for example). Precautions Depth perception (stereopsis) develops around the age of three months old. For successful development of binocular vision and the ability to perceive three-dimensionally, the surgery should not be postponed past the age of four. The earlier the surgery the better the outcome, so an early diagnosis is important.

Surgery may even be performed before two years old. After surgery, if binocular vision is to develop, corrective lenses and eye exercises (vision therapy) will probably be necessary. Description The extraocular muscles attach via tendons to the sclera (the white, opaque, outer protective covering of the eyeball) at different places just behind an imaginary equator circling the top, bottom, left, and right of the eye. The other end of each of these muscles attaches to a part of the orbit (the eye socket in the skull). These muscles enable the eyes to move up, down, to one side or the other, or any angle in between. Normally both eyes move together, receive the same image on corresponding locations on both retinas, and the brain fuses these images into one three-dimensional image. The exception is in strabismus which is a disorder where one or both eyes deviate out of alignment, most often outwardly (exotropia) or toward the nose (esotropia). The brain now receives two different images, and either suppresses one or the person sees double (diplopia). This deviation can be adjusted by weakening or strengthening the appropriate muscles to move the eyes toward the center.

For example, if an eye turns upward, the muscle at the bottom of the eye could be strengthened. Rarely, eye muscle surgery is performed on people with nystagmus or Duane syndrome. Nystagmus is a condition where one or both eyes move rapidly or oscillate; it can sometimes be helped by moving the eyes to the position of least oscillation. Duane syndrome is a disorder where there is limited horizontal eye movement; it can sometimes be relieved by surgery to weaken an eye muscle. There are two methods to alter extraocular muscles. Traditional surgery can be used to strengthen, weaken, or reposition an extraocular muscle. The surgeon first makes an incision in the conjunctiva (the clear membrane covering the sclera), then puts a suture into the muscle to prevent it from getting lost and loosens the muscle from the eyeball with a surgical hook. During a resection, the muscle is detached from the sclera, a piece of muscle is removed so the muscle is now shorter, and the muscle is reattached to the same place. This strengths the muscle. In a recession, the muscle is made weaker by repositioning it. More than one extraocular eye muscle might be operated on at the same time.

Another way of weakening eye muscles, using botulinum toxin injected into the muscle, was introduced in the early 1980s. Although the botulinum toxin wears off, the realignment may be permanent, depending upon whether neurological connections for binocular vision were established during the time the toxin was active. This technique can also be used to adjust a muscle after traditional surgery. The cost of eye muscle surgery is about $2,000-$4,000, and about 700,000 surgeries are performed annually in the United States. Preparation Patients should make sure their doctors are aware of any medications that they are taking, even over-the-counter medications. Patients should not take aspirin, or any other blood-thinning medications for ten days prior to surgery, and should not eat or drink after midnight the night before. Aftercare Patients will need someone to drive them home after their surgery. They should continue to avoid aspirin and other non-steroidal anti-inflammatory agents for an additional three days, but they can take acetaminophen (e.g., Tylenol). Patients should discuss this with the surgeon to be clear what medications they can or cannot take.

Pain will subside after two to three days, and patients can resume most normal activities within a few days. Again, this may vary with the patient and the patient should discuss returning to normal activity with the surgeon. They should not get their eyes wet for three to four days and should refrain from swimming for 10 days. Operated eyes will be red for about two weeks. Risks As with any surgery, there are risks involved. Eye muscle surgery is relatively safe, but very rarely a cut muscle gets lost and can not be retrieved. This, and other serious reactions, including those caused by anesthetics, can result in vision loss in the affected eye. Occasionally, retinal or nerve damage occurs. Double vision is not uncommon after eye muscle surgery. As mentioned earlier, glasses or vision therapy may be necessary. Normal results Cosmetic improvement is likely with success rate estimates varying from about 65-85%. According to the best statistics as of 1998, binocular vision is improved in young children about 35% of the time. There is no improvement, or the condition worsens 15-35% of the time. A second operation may rectify less-than-perfect outcomes. Resources

Question: What is the technical term for double vision?
Answer: Diplopia