Strabismus prevents bringing the gaze of both eyes to the same point in space

Strabismus, also known as "heterotropia", "squint", "crossed eye", "wandering eye", or "wall eyed", is a disorder in which the eyes do not point in the same direction. It typically involves a lack of coordination between the extraocular muscles which prevents bringing the gaze of each eye to the same point in space, preventing proper binocular vision, which may adversely affect depth perception. The cause of strabismus can be a disorder in one or both of the eyes; for example, nearsightedness or farsightedness, making it impossible for the brain to fuse two different images. The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... A mild case of strabismus. ... A mild case of strabismus. ... Disorder may refer to : A disease, in medicine Randomness (lack of order), in information theory This is a disambiguation page — a list of pages that otherwise might share the same title. ... This article refers to the sight organ. ... Categories: Anatomy stubs | Muscular system | Eye ... Binocular vision is vision in which both eyes are used synchronously to produce a single image. ... Depth perception is the visual ability to perceive the world in three dimensions. ...

When strabismus is congenital or develops in infancy, it can cause amblyopia, in which the brain ignores input from the deviated eye although it is capable of normal sight. Since strabismus can cause amblyopia, which is sometimes referred to as lazy eye, it is sometimes itself inaccurately referred to as lazy eye. A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... A human infant The word Infant derives from the Latin in-fans, meaning unable to speak. ... Amblyopia, or lazy eye, is a disorder of the eye. ... Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Amblyopia, or lazy eye, is a disorder of the eye. ...

In addition to the visual problem, strabismus can be considered a cosmetic problem owing to the appearance of the deviated eye. One study reported that 85% of adult strabismus patients "reported that they had problems with work, school and sports because of their strabismus". The same study also reported that 70% said strabismus "had a negative effect on their self-image" [1]. Cosmetic refers to beauty or appearance, especially concerning the human body. ... American high school students in a school A school is most commonly a place designated for learning. ... A persons self image is the mental picture, generally of a kind that is quite resistant to change, that depicts not only details that are potentially available to objective investigation by others (height, weight, hair color, nature of external genitalia, I.Q. score, is this person double-jointed, etc. ...

Types

Strabismus may be concomitant or incomitant. Concomitant strabismus means that the strabismus is equal regardless of which direction the gaze is targeted. This indicates that the individual extraocular muscles function individually, but that they may simply not be aimed at the same target. Concomitant strabismus in a child under the age of 6 rarely indicates serious neurologic disorder. Blindness in one eye usually causes concomitant strabismus, with the eye of a child turning inward, and that of an adult turning outward. The extraocular muscles are the six muscles that control the movements of the eye. ... Neurology is a branch of medicine dealing with the nervous system and its disorders. ...

Incomitant strabismus occurs when the degree of misalignment varies with the direction of gaze. This indicates that one or more of the extraocular muscles may not be functioning normally. Types of strabismus include:

• esotropia, or one eye turning inward;
• exotropia, or one eye turning outward;
• hypertropia, or one eye turning upward.
• hypotropia, or one eye turning downward.

Medial strabismus manifests as the inability to abduct (move laterally) one's eye. This is usually caused by damage to the abducens nerve or abducens nucleus. The result is that the eye in its normal resting state deviates medially, as the movements of the medial rectus muscle are less opposed by the denervated lateral rectus muscle. Person exhibiting esotropia of the right eye Esotropia is a form of strabismus where one or both of the eyes turn inward (often called lazy eye). The most common type of esotropia occurs in approximately one to two percent of the population. ... Exotropia is a form of strabismus where the eyes are deviated outward. ... The sixth out of twelve cranial nerves, the abducens nerve controls the lateral rectus muscle - this means that the action of this nerve controls each eyes ability to look laterally (away from the midline). ... The abducens nucleus is the originating nucleus from which the abducens nerve emerges - a cranial nerve nucleus. ... The medial rectus muscle is a muscle in the orbit that adducts the eyeball (makes it move inwards). ... The lateral rectus muscle is a muscle in the orbit that abducts the eyeball (makes it move outwards). ...

Pseudostrabismus is the false appearance of strabismus. It generally occurs in infants and toddlers whose bridge of their nose is wide and flat. This causes the appearance of strabismus. With age the bridge of the child's nose will narrow and the folds in the corner of the eyes will go away. To detect the difference between pseudostrabismus and strabismus use a flashlight and shine it in the child's eyes. When the child is looking at the light a reflection can be seen on the front surface of the pupil. If the eyes are properly aligned with one another then the reflection will be in the same spot of each eye. If strabismus is present, then the reflection from the light will not be in the same spot of each eye. Pseudostrabismus is the false appearance of crossed eyes. ... Pseudostrabismus is the false appearance of crossed eyes. ...

Diagnosis

If the eye being tested is the strabismic eye, then it will fixate on the object after the "good" eye is covered. If it is the "good" eye, there will be no change in fixation, as it is already fixated. Depending on the direction that the strabismic eye deviates, the type of tropia or phoria may be assessed.

Treatment and management

As with other binocular vision disorders, the primary therapeutic goal for those with strabismus is comfortable, single, clear, normal binocular vision at all distances and directions of gaze [2].

If minor and detected early, strabismus can often be corrected with enforced use of an eyepatch on the dominant eye and/or vision therapy. Advanced strabismus is usually treated with a combination of eyeglasses or prisms, vision therapy, and surgery, depending on the underlying reason for the misalignment. Surgery attempts to align the eyes by shortening, lengthening, or changing the position of one or more of the extraocular eye muscles, and is frequently the only way to achieve cosmetic improvement. Glasses affect the position by changing the person's reaction to focusing. Prisms change the way light, and therefore images, strike the eye, simulating a change in the eye position. An eyepatch is a small patch, usually of black cloth, that is worn in front of one eye and usually attached around the head by an elastic band or by a string. ... Vision therapy, also known as visual therapy or visual training, is a broadly-defined set of treatment programs related to the improvement of visual health and comfort. ... Glasses, spectacles, or eyeglasses are frames bearing lenses worn in front of the eyes, sometimes for purely aesthetic reasons but normally for vision correction or eye protection. ... If a shaft of light entering a prism is sufficiently small such that the coloured edges meet, a spectrum results In optics, a prism is a device used to refract light, reflect it or break it up (to disperse it) into its constituent spectral colours (colours of the rainbow). ... Vision therapy, also known as visual therapy or visual training, is a broadly-defined set of treatment programs related to the improvement of visual health and comfort. ... Eye surgery, also known as ophthalmic surgery or ocular surgery, is a surgical procedure performed on the eye or its adnexa typically by an ophthalmologist . ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength. ...

Early treatment of strabismus in infancy can reduce the chance of developing amblyopia and depth perception problems. Eyes that remain misaligned can still develop visual problems. Although not a cure for strabismus, prism lenses can also be used to provide some comfort for sufferers and to prevent double vision from occurring. A lens. ...

In adults with previously normal alignment, the onset of strabismus usually results in double vision (diplopia). The term adult describes any mature organism, but normally it refers to a human: one that is no longer a child / minor and is now either a man or a woman. ... Diplopia is the medical term for double vision. ...

Advocates of the Bates method assert that it can reverse strabismus [3], however, this claim is rejected by the vast majority of mainstream eyecare professionals. The Bates Method is a controversial system of practices that are claimed to improve sight and reverse ocular disorders to normal by eliminating mental strain and restoring the natural habits of seeing. ...

Wikibook

• Perfect Sight Without Glasses, chapter 21 and 22, author W.H. Bates.

See also

• Duane syndrome
• Orthoptics
• Sixth (abducent) nerve palsy

Duane syndrome (DS) is a rare, congenital (present from birth) eye movement disorder. ... Orthoptics, which literally means straightening of the eyes, dates back to the 1850s. ... Sixth (abducent) nerve palsy is a disorder associated with dysfunction of cranial nerve VI (the abducens nerve), which is responsible for moving the eye to the side. ...

External links

• All About Strabismus - All Types, All Treatments
• Convergence Insufficiency - Common Condition Confused with Strabismus
• Eye Muscle Surgery for Strabismus - FAQ
• Lazy Eye and Strabismus are Not Same Condition
• Have fun with strabismus
• VisionSimulations.com | What the world looks like to people with various diseases and conditions of the eye
• Practical approach to diagnosis of strabismus