FAQs

Frequently Asked Questions (FAQs) are composed and periodically reviewed by pediatric ophthalmologists and certified orthoptists from the Public Information Committee of AAPOS. For questions or suggestions regarding FAQs please contact us.

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AAPOS: The American Association for Pediatric Ophthalmology and Strabismus

AAPOS is the American Association for Pediatric Ophthalmology and Strabismus. The organization's goals are to advance the quality of children's eye care, support the training of pediatric ophthalmologists, support research activities in pediatric ophthalmology, and advance the care of adults with strabismus.
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Abnormal Head Position

An abnormal head posture or position occurs when the eyes are not looking directly at the target of interest. Abnormal head positions can include chin up, chin down, head tilted to the right or left, and face turns to the right or left. The abnormal position of the head could be due to an ocular or a non- ocular problem.
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Accommodative Esotropia

Accommodative esotropia or refractive esotropia is eye crossing that is caused (partially or wholly) by focusing efforts of the eyes as they try to see clearly.
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Achromatopsia

Achromatopsia is a non-progressive visual disorder which is characterized by decreased vision, light sensitivity, and the absence of color vision.
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Adjustable Sutures in Strabismus Surgery

Adjustable suture surgery is a technique that allows for change in eye muscle position in the immediate postoperative period. It may improve the chance for desired eye alignment.
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Treatment Options for Adult Strabismus

Recent treatment advances allow most adults with misaligned eyes to have surgical correction.
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Albinism

The word albinism refers to a large group of inherited conditions. People with albinism have little or no pigment in their eyes, skin, and/or hair. They have inherited genes that do not make the usual amounts of melanin, the major pigment giving color to our skin and eyes.
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Allergic Conjunctivitis

Allergic conjunctivitis is a reaction of the eye to things in the environment such as dust, pollen, animal dander, and medications.
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Amblyopia

Amblyopia or "lazy eye" is a common vision problem in children and is responsible for vision loss in more children than all other causes combined. Amblyopia is decreased vision of a child that results when one or both eyes send a blurry image to the brain.
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Anesthesia for Adults having eye surgery

A “general,” “local,” or “topical”anesthesia is necessary during all kinds of surgery to reduce or eliminate pain. Eye surgery is no exception.
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Anesthesia for Children having eye surgery

A “general” or “local” anesthesia is necessary during all kinds of surgery to reduce or eliminate pain. Eye surgery is no exception.
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Anatomy of the Eye

The human eye is a complex structure.  The following list describes the parts of the eye in detail.
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Aniridia

Aniridia means an absence of the iris or the colored part of the eye. A small rim of iris may be visible only with use of a special instrument by an ophthalmologist. The pupil is large and the condition in present in both eyes.
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Anisocoria and Horner's Syndrome

The term anisocoria refers to pupils that are different sizes at the same time. The presence of anisocoria can be normal, or it can be a sign of a medical condition. In Horner’s syndrome, the pupil in the involved eye is usually smaller and does not dilate as well as the other eye.
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Astigmatism (distorted sight): a Refractive Error

Refractive errors are the result of the eye improperly focusing light on the retina.  The following list of conditions are the result of refractive errors. 
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Bell’s Palsy

Bell’s palsy, is a weakness of the muscles of the face that comes on suddenly and is not caused by any known underlying condition. Bell’s palsy is also known as idiopathic facial palsy (“idiopathic” means of unknown cause and “palsy” means paralysis). Although more common in adults, Bell’s palsy can occur in children.
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Blowout Fracture/Orbital Fracture

A blowout fracture is a fracture of one or more of the bones surrounding the eye and is commonly referred to as an orbital floor fracture.
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Brown Syndrome

Brown syndrome (named after Dr. Harold W. Brown) is also known as Superior Oblique Tendon Sheath syndrome. It is a mechanical problem in which the superior oblique muscle/tendon (on the outside of the eyeball) does not move freely.
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Capillary Hemangioma

A capillary hemangioma (“strawberry” birthmark) is a benign, abnormal overgrowth of blood vessels.
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Cataract

A cataract is any cloudiness or opacity of the normally clear lens of the eye. Cataract size ranges from very small to entire lens involvement.
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Cellulitis

Preseptal cellulitis is swelling of the superficial or anterior portion of the eyelid in front of the septum. The septum is a sheet of connective tissue that separates the anterior superficial eyelid from the orbit (bony socket that contains the eye).
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Chalazion (stye)

A chalazion is a bump in the eyelid that is usually about the size of a small pea although it is occasionally smaller or larger. More than one chalazion can occur in an eyelid at the same time.
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Coats Disease

Coats disease is a congenital abnormality of retinal blood vessels. The dilated vessels leak fluid which may cause exudates to deposit in the retina and possibly lead to retinal detachment.
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Coloboma

A coloboma is a congenital defect in the structure of either the eyelid or the eye.
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Congenital Nasolacrimal Duct Obstruction

Tears normally drain through small openings in the corners of the upper and lower eyelids called puncta and enter the nose through the nasolacrimal duct. Tear duct obstruction prevents tears from draining through this system normally.
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Conjunctivitis

Conjunctivitis or "pink eye" is a condition where the eyes look pink or red and may have discharge. Symptoms may include burning, irritation, discharge, or crusting of the lashes.
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Convergence Insufficiency

Convergence insufficiency is the inability to maintain binocular function (keeping the two eyes working together) while working at a near distance. Typically, one eye will turn outward (intermittent exotropia) when focusing on a word or object from closer than a certain distance.
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Corneal Abrasion

A corneal abrasion is a scratch or cut on the surface of the cornea. The cornea is the clear part on the front part of the eye. It covers the colored part of the eye, the iris.
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Cortical Visual Impairment

Cortical visual impairment (CVI) is decreased visual response in both eyes due to an abnormality affecting the part of the brain responsible for sight. It is one of the most frequent causes of visual impairment in children from developed countries.
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Cranial Nerve Palsy

The brainstem connects the spinal cord to the brain.  The brainstem performs spinal-cord like functions for the head.  The cranial nerves emanate from the brainstem.  They provide sensory and motor functions that deal with the special senses (olfaction, sight, hearing, equilibrium, and taste). 
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Cranial Nerve VI (6) Palsy/Abducens Palsy

Sixth cranial nerve palsy is weakness of the nerve that innervates the lateral rectus muscle. The lateral rectus muscle pulls the eye away from the nose and when the lateral rectus muscle is weak, the eye turns inward toward the nose (esotropia). The esotropia is larger  on distance fixation and  on gaze to the same side as the affected lateral rectus muscle.
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Dermoid Cyst

A dermoid is an overgrowth of normal, non-cancerous tissue in an abnormal location. Dermoids occur all over the body. The ones in and around the eye are usually comprised of skin structures and fat.
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Diabetes Mellitus and Diabetic Retinopathy

Diabetes mellitus is a group of metabolic diseases characterized by elevated blood glucose levels resulting from defects in insulin secretion, insulin action, or both. Diabetes may cause blood vessels in the retina (the light sensitive lining of the eye) to become damaged (leaky or blocked) or grow abnormally.
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Dilating Eye Drops

Dilating eye drops contain medication to enlarge (dilate) the pupil of the eye. There are two types of drops: one type stimulates contraction of the muscles that enlarge the pupil (such as phenylephrine); the other type relaxes the muscles that make the pupil constrict (such as cyclopentolate).
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Dissociated Vertical Divergence (DVD)

DVD is a condition in which one eye drifts upward. The eye may drift upward only occasionally or be deviated almost constantly.
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Down Syndrome and the Eyes

Down syndrome is caused by a duplication of all or part of chromosome 21 making three copies of the chromosome rather than the usual two copies. Individuals with Down syndrome are at increased risk for a variety of eye and vision disorders.
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Duane Syndrome

Duane syndrome, also called Duane retraction syndrome (DRS), is a group of eye muscle disorders that cause abnormal eye movements. People with Duane syndrome have difficulty rotating one or both eyes outward (abduction) or inward (adduction).
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Endophthalmitis

Endophthalmitis is an infection inside the eyeball (globe).
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Esotropia

A type of strabismus in which one or both eyes turn inward. It can be intermittent or constant.
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Exotropia

Exotropia refers to eyes that turn outward. It is the opposite of crossed eyes, or esotropia.
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Eye Safety Questions and Answers

The following list addresses common questions related to eye safety.
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Fetal Alchohol Syndrome

Fetal Alcohol Syndrome (FAS) describes changes in a baby born to a mother whose pregnancy was complicated by alcohol consumption.
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Fitting Glasses for Children

What is the proper frame for my child? How do I know the glasses fit? How can I tell if the bifocal is the proper height? Which optical shop should I use?
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Fourth Nerve Palsy/Superior Oblique Palsy/Trochlear Palsy

A superior oblique palsy is a weakness of the superior oblique muscle, one of the extra ocular muscles of the eye. A palsy refers to a complete weakening of the muscle while a paresis is a partial weakening. This condition is usually unilateral (one eye) but can be bilateral (both eyes). As the fourth cranial nerve innervates the superior oblique, this is also known as a fourth nerve palsy. 
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Glasses for Children: Questions and Answers

The following list addresses comon questions about glasses for children.
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Glaucoma

Glaucoma is a group of diseases characterized by damage to the optic nerve that often occurs when the eye pressure is elevated and can result in severe vision loss.
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Headaches in Children: Questions and Answers

The following list addresses common questions about headaches in children.
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Herpes-related Eye Disease

Herpes is a family of viruses with many different subtypes. Eye infections and mouth cold sores are most commonly caused by Herpes Simplex Virus (HSV) Type I.
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Hyperopia (farsighted): a Refractive Error

Refractive errors are the result of the eye improperly focusing light on the retina.  The following list of conditions are the result of refractive errors. 
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Hyphema

A hyphema is an accumulation of blood in the space between the cornea and the iris.
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Idiopathic intracranial hypertension?

Idiopathic intracranial hypertension (IIH) is a disorder that results from an increase in the pressure of the Cerebro-Spinal Fluid (CSF) that cushions and protects the brain and spinal cord. The CSF is constantly produced in the brain and reabsorbed back into the bloodstream at a fairly constant rate.  This allows the fluid pressure around the brain to remain constant.
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Infantile Esotropia

Esotropia is an inward turning of one or both eyes. Infantile esotropia begins at birth or during the first year of life. Infantile esotropia is also called congenital esotropia.
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Intraocular Lens Implant (IOL)

An intraocular lens implant is a synthetic, artificial lens placed inside the eye that replaces the focusing power of a natural lens that is surgically removed, usually as part of cataract surgery (see cataracts).
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Iritis

Iritis is inflammation of the iris.
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Juvenile Idiopathic Arthritis/Juvenile Rheumatoid Arthritis

Juvenile Idiopathic Arthritis is defined as arthritis (inflammation of the joints) of greater than 3 months' duration with onset at less than 16 years of age.
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Keratoconus

Keratoconus is a condition that is due to progressive steepening of the cornea resulting in a "cone" shaped appearance. The cornea becomes thin near the center and may lead to myopia (near sightedness) and/or severe astigmatism. It is usually bilateral and typically begins to develop during adolescence.
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Learning Disabilites and the Visual System

Learning disability is a lifelong condition which interferes with the ability to learn. This includes: learning to read, reading comprehension, writing and spelling, mathematical operations, learning a foreign language, and organizing written and spoken language. Individuals with LD may be particularly gifted in other skills and are typically of normal intelligence.
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Leber's Congenital Amaurosis

Leber Congenital Amaurosis (LCA) is an inherited condition in which findings commonly first appear after 2-3 months of age. LCA affects both the rods and cones (cells which detect light) of the retina.
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Leukocoria

Leukocoria means "white pupil." It occurs when the pupil (the round hole in the colored part of the eye) is white rather than the usual black.
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Marfan Syndrome

The Marfan syndrome is a heritable condition that affects the strength of the connective tissues that hold parts of the body together and provide a framework for growth and development. Because connective tissue is found throughout the body, patients with Marfan syndrome have problems with a number of systems including the skeleton, eyes, heart and blood vessels, nervous system, skin and lungs.
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Molluscum Contagiosum

Molluscum contagiosum is a common viral infection in children. It causes bumps on the skin including the eyelids and eyelid margins (ocular molluscum). The bumps are usually pearl-like and dome-shaped with a central crater (umbilication).
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Monocular Elevation Deficiency/ Double Elevator Palsy

Monocular Elevation Deficiency, also known by the older term Double Elevator Palsy, is an inability to elevate one eye, usually resulting in one eye that is pointed downward relative to the other eye (hypotropia).
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Myasthenia Gravis

Myasthenia gravis is an autoimmune disease in which antibodies attack normal skeletal muscle tissue and render it weak. It occurs in both children and adults and can affect different muscle groups in the body.
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Myopia (nearsighted): a Refractive Error

Refractive errors are the result of the eye improperly focusing light on the retina.  The following list of conditions are the result of refractive errors. 
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Neurofibromatosis

Neurofibromatosis is a condition characterized by multiple growths which derive from primitive cells in the body. The growths occur along nerve paths, anywhere in the body. Neurofibromatosis skin lesions are typically flat, pigmented patches but occasionally are elevated flesh-colored bumps.
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Nystagmus

Nystagmus is an involuntary, shaking, “to and fro” movement of the eyes.
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Optic Nerve Atrophy

Optic nerve atrophy (ONA) is mild to severe damage to the optic nerve that can adversely affect central vision, peripheral vision and color vision.
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Optic Nerve Drusen

Optic nerve drusen are abnormal globular concretions of protein and calcium salts which accumulate in the optic nerve and usually become visible after the first decade of life. They occur in both eyes more often than just one.
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Optic Nerve Hypoplasia

Optic nerve hypoplasia (ONH) is a congenital condition in which the optic nerve is underdeveloped (small).
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Optic Neuritis

Optic neuritis is a condition that involves inflammation of the optic nerve. The optic nerve carries the visual signal from the eye to the brain.
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Orthoptist and Orthoptics: Questions and Answers

Certified orthoptists are allied health professionals uniquely trained in evaluation and management of children and adults with eye movement abnormalities. They practice orthoptics and are recognized among the highest levels of ophthalmic medical personnel.
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Patching Tips for Parents

Patching is sometimes recommended when children are diagnosed with amblyopia or lazy eye. It works by handicapping the eye with normal vision so that the vision in the poorer seeing amblyopic eye improves. The following list includes patching tips for parents.
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Pediatric Ophthalmologist

All ophthalmologists have training in children’s eye problems, but the pediatric ophthalmologist has had additional training and practice in examining children and caring for their eye problems. If your primary care doctor suggests that your child have his or her eyes checked, a pediatric ophthalmologist will have the greatest knowledge of the possible conditions and the greatest experience in examining children effectively.
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Pseudostrabismus

Strabismus is the medical term for eye misalignment. Pseudostrabismus refers to a false appearance of strabismus. Most often the eye(s) have the false appearance of turning inward.
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Pterygium

Pterygium means "wing" and refers to a wing-like growth that spreads over the cornea. Pterygia are more common in warm climates such as the tropics and are associated with early exposure to the sun (especially during childhood and teen years).
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Ptosis (tow-sis)

A droopy eyelid or ptosis can be present at birth (congenital) or occur later in life (acquired). Poor development of the levator palpebris muscle in the upper eyelid with resulting abnormal function is the most common cause of congenital ptosis. Acquired ptosis has many causes. Ptosis can involve one or both upper eyelids, with or without asymmetry.
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Refractive Errors: Myopia (nearsighted), Hyperopia (farsighted), Astigmatism (distorted sight)

Refractive errors are the result of the eye improperly focusing light on the retina.  The following list of conditions are the result of refractive errors.
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Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a group of diseases characterized by a gradual loss of vision (night and peripheral, predominantly) caused by changes in the retina (pigment and neural cells, blood vessels, etc).
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Retinoblastoma

Retinoblastoma is a malignant tumor of the eye(s) that originates from the retina (light-sensitive lining of the eye). One (unilateral) or both (bilateral) eyes may be affected and typically occurs in children less than 5 years old.
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Retinopathy of Prematurity (ROP)

Retinopathy of prematurity (ROP) is a potentially blinding disease caused by abnormal development of retina blood vessels in premature infants.
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Retinoschisis (Congenital X-linked Retinoschisis, Juvenile X-linked Retinoschisis)

The retina is the back part of the eye that sends images to the brain. The retina consists of ten layers with the inside surface consisting primarily of nerve fibers. The term “schisis” means split. Hence retinoschisis is a split in the layers of the retina.
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Retinoscopy: How We Determine Glasses for Nonverbal Children

Retinoscopy is a technique to determine objectively the refractive error of the eye (farsighted, nearsighted, astigmatism) and the need for glasses. The test can be quick, easy, reliably accurate and requires minimal cooperation from the patient.
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Rubinstein-Taybi Syndrome

Rubinstein-Taybi syndrome (RTS) is a genetic multi-system disorder characterized by facial abnormalities, broad thumbs and great toes, and developmental disability.
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Shaken Baby Syndrome

Shaken baby syndrome (SBS) is a constellation of findings (including serious brain injury) that occurs when a baby is shaken repeatedly or the head impacts a hard object.
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Sixth Nerve Palsy/Abducens Palsy

Sixth cranial nerve palsy is weakness of the nerve that innervates the lateral rectus muscle. The lateral rectus muscle pulls the eye to the side, away from the nose. An eye affected by sixth nerve palsy turns inward (esotropia). The esotropia is larger when looking at a distance and also to the same side as the affected lateral rectus muscle.
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Stickler Syndrome

 Stickler syndrome is a progressive genetic disorder of connective tissue throughout out the body.
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Strabismus

Strabismus is any misalignment of the eyes.
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Strabismus Measurements and Techniques

Strabismus is measured in several different ways, depending on the level of cooperation of the patient. Light reflex tests are easiest to perform, and cover testing requires more cooperation and is more accurate.
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Strabismus Surgery

Strabismus surgery strengthens or weakens eye muscles, which changes the alignment of the eyes relative to each other.
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Sturge-Weber Syndrome

Sturge-Weber syndrome is characterized by a reddish discoloration of the skin on one side of the face (port wine stain) and malformation of blood vessels of the brain.
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Superior Oblique Palsy/Trochlear Palsy/Fourth Nerve Palsy

A superior oblique palsy is a weakness of the superior oblique muscle, one of the extra ocular muscles of the eye. A palsy refers to a complete weakening of the muscle while a paresis is a partial weakening. This condition is usually unilateral (one eye) but can be bilateral (both eyes). As the fourth cranial nerve innervates the superior oblique, this is also known as a fourth nerve palsy.
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Third Nerve (Cranial Nerve III [3]) Palsy/Oculomotor Palsy

Palsy or weakness of the third cranial nerve causes loss of movement of the eye up, down, and in as well as drooping (ptosis) of the upper eyelid. In a complete palsy, the pupil may be enlarged, and the ability of the eye to focus at near (accommodate) may be impaired. The weakness of the third nerve may be partial or complete.
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Thyroid Eye Disorders

The following list details several disorders that are the result of a malfunctioning thyroid gland.
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Toxoplasmosis

Toxoplasmosis is an infection with the protozoan intracellular parasite Toxoplasma gondii. In the eye, Toxoplasma infections frequently cause significant inflammation and subsequent scarring which may temporarily or permanently impair vision.
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Vision Screening

Vision screening is an efficient and cost-effective method to identify children with visual impairment or eye conditions that are likely to lead to visual impairment so that a referral can be made to an appropriate eye care professional for further evaluation and treatment.
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Vision Therapy

The term "vision therapy" refers to techniques and exercises used to treat visual processing disorders, perceptual disorders or eye muscle balance disorders.
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What causes Williams Syndrome?

Williams Syndrome is caused by a deletion of genetic material from a specific region of chromosome 7.   It is a rare disorder and is also called Elfin Facies Syndrome.
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