black eye Bleeding into the tissues around the EYE resulting from trauma to the area, such as a blow or surgical OPERATION. As with any other bruise, the bleeding causes swelling and discoloration. The most significant concerns with a black eye are damage to the eye or fractures of the orbital bones, which require immediate medical attention.
Seek immediate medical attention if these symptoms accompany a black eye:
• seeing dark spots (FLOATERS) or flashes of light
• any cuts on the insides of the eyelids or on the eye
• blurry, distorted, or double vision
• numbness on same side of the face
• trouble moving the eye to look up, down, or to either side
Treatment for a simple black eye is cold to the area as quickly as possible after the injury occurs and at frequent intervals during the first 24 hours or until the PAIN subsides and the swelling stabilizes. A black eye may take two weeks to fully heal, and undergoes a number of color changes as HEALING progresses. People who participate in sports such as softball, baseball, basketball, tennis, racquetball, soccer, and similar events should wear appropriate eye protection.
blepharitis INFLAMMATION of the eyelids. The most common causes of blepharitis are INFECTION and irritation. Anterior blepharitis is INFLAMMATION of the outer surface of the eyelid, typically along the rim at the base of the eyelashes. Posterior blepharitis affects the inner surface of the eyelid, typically resulting from blocked oil glands (meibomian glands) along the eyelid. Symptoms of either form of blepharitis may include
• itching or burning sensation
• crusting along the eyelids, especially upon awakening
• swelling and redness
• PHOTOPHOBIA (excessive light sensitivity)
• excessive tearing
• blurry vision
Blepharitis may develop as a result of other conditions such as DERMATITIS or ROSACEA (disorders that cause SKIN inflammation). When this is the case, treatment targets the underlying condition. When the cause of the inflammation is bacterial, treatment is topical and sometimes oral ANTIBIOTIC MEDICATIONS. Occasionally the viruses HERPES SIM- PLEX I (which causes cold sores) and HERPES ZOSTER (which causes shingles) can infect the eyes. Viral infections such as these cause symptoms until they run their course, typically in 7 to 10 days. Whatever the cause of the inflammation, moist, warm compresses help loosen crusted secretions and keep the eyelids clean. EYE care professionals recommend gently washing the eyelids with a mixture of water and baby (tear-free) shampoo. Blepharitis tends to be chronic so good eyelid hygiene helps minimize recurrences as well as discomfort during episodes.
blepharoplasty A surgical OPERATION to remove excess tissue from the eyelids to correct drooping upper eyelids and “baggy” lower eyelids. Such conditions most commonly develop as a consequence of aging or extensive weight loss or when there is damage to the nerves that control the eye- lid muscles (such as with PARKINSON’S DISEASE). An ophthalmologist or a plastic surgeon performs blepharoplasty, usually as an AMBULATORY SURGERY (also called outpatient or same-day surgery). Recovery takes two to four weeks; there can be significant swelling, bruising, and discoloration especially during the first two weeks after the operation. Cold compresses help reduce these symptoms. The risks of blepharoplasty include excessive bleeding and INFECTION.
See also BLACK EYE; BLEPHAROSPASM; PLASTIC SUR- GERY; PTOSIS; RHINOPLASTY; RHITIDOPLASTY; SURGERY BENEFIT AND RISK ASSESSMENT.
blepharospasm Involuntary closure of the eyelid that results from dysfunction of or damage to the nerves that control the muscles of the eyelids. Episodes of closure may range from brief (a minute) to extended (several hours). Extended closure interferes with vision. Doctors do not know what causes blepharospasm, though it is a symptom of numerous neurologic and neuromus- cular disorders that affect MUSCLE control such as PARKINSON’S DISEASE and DYSTONIA. Blepharospasm that develops without an apparent underlying dis- order is benign essential blepharospasm. Ble- pharospasm often begins with minor twitches and tics or squinting, progressing over time to forceful and prolonged contraction of the eyelid muscles. PHOTOPHOBIA (sensitivity to light) is common. Fatigue and CAFFEINE may initiate episodes of spasms.
The diagnostic path may include a NEUROLOGIC EXAMINATION to determine whether underlying neurologic disorders exist. Blepharospasm requires treatment when it begins to interfere with the activities of everyday life. Moderate blepharospasm often responds to MUSCLE RELAXANT MEDICATIONS such as clonazepam (Klonopin) or Lioresal (Baclofen), or to medications used to treat Parkinson’s disease such as levodopa. Many people obtain long-term relief from injections of botulinum toxin, which temporarily paralyzes the eyelid muscles. Surgery to remove muscle tissue (myectomy) or to cut the nerves supplying the eyelid muscles (neurectomy) may provide relief. Though therapeutic measures can control symptoms, as yet there is no cure for blepharospasm.
See also BOTULINUM THERAPY; PTOSIS; SURGERY BEN- EFIT AND RISK MANAGEMENT; TIC.
blindness See VISION IMPAIRMENT.
braille A tactile (touch-based) system of written language that features patterns of raised dots to represent letters of the alphabet, common words and contractions, mathematical symbols, and punctuation. Named after its developer, Louis Braille (1809–1852), braille allows people who are blind to read and, with adaptive typewriters and computer technology, to write. Six dots, in two columns of three dots each, form the foundation for braille; the presence or absence of dots in specific patterns identifies the letter, number, symbol, or concept. There are a number of braille variations, or codes, in common use in the United States. The major ones are these:
• American literary braille code uses about 250 patterns to create book-length materials using short-form words, contractions, single-cell words, and symbols; patterns may have multiple meanings interpreted by context.
• Grade 2 braille code is an abbreviated variation of American literary braille code used primarily for recreational reading materials such as novels and nonacademic nonfiction.
• Grade 1 braille code is the basic alphabet and numerals 0 through 9.
• Nemeth braille code contains about 600 unique, specialized patterns that are distinct from American literary braille code for use in mathematics and science.
• Computer braille code provides a mix of American literary braille code, Nemeth braille code, and unique symbols for computer programming and instruction documentation.
• Music braille code is specialized for transcribing musical scores.
Learning each variation of braille code is like learning a different language. Most people learn the one or two variations they are most likely to use. People whose vision is intact also can learn braille, and should if they have regular interactions with people who are blind. Many communities have schools and consultants who teach braille as well as libraries that provide braille publications. Most public signage in the United States includes braille translations.
See also VISION IMPAIRMENT.
bullous keratopathy Swelling (edema) and blistering of the CORNEA. Bullous keratopathy most commonly develops as a complication following CATARACT EXTRACTION AND LENS REPLACEMENT or other surgery on the EYE, though it also may develop as a consequence of chronic irritation such as might occur with DRY EYE SYNDROME.
The healthy cornea is about 75 percent water. One function of the cells that surround the cornea is to maintain this fluid balance. Irritation and trauma that damage these cells diminishes their ability to function, and the cornea retains more water. The swelling stretches the surface of the cornea, pushing the cornea into closer contact with the eyelid and resulting in further irritation. Bullae, or blisters, develop as the cornea’s attempt to relieve the discomfort, much as blisters develop on the feet or hands in reaction to friction.
Early symptoms of bullous keratopathy are a sensation of grittiness in the eye, blurred vision, excessive tearing, and PHOTOPHOBIA (sensitivity to light). When bullae form, and especially when they rupture, the PAIN often is severe. The ophthalmologist can diagnose bullous keratopathy using SLIT LAMP EXAMINATION of the cornea, a pain- less procedure that combines an intense light focused in a slit with magnification through a ophthalmologic microscope. Eye drops or ointment with a higher saline concentration than tears helps draw fluid out of the cornea, reducing the swelling. Soft contact lenses, which absorb fluid from the eye and shield the cornea from con- tact with the eyelid, relieve discomfort for many people. Bullous keratopathy tends to be chronic, and over time may result in damage to the cornea that requires the cornea’s surgical removal (kera- totomy) or CORNEAL TRANSPLANTATION.
See also BLISTER; KERATITIS; UVEITIS.