Amblyopia

Amblyopia: The brain and the eye work together to produce vision. Light enters the eye and is changed into nerve signals that travel along the optic nerve to the brain. Amblyopia is the medical term used when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye itself looks normal, but it is not being used normally because the brain is favoring the other eye. This condition is also sometimes called lazy eye. Amblyopia is the most common cause of decreased vision in children. The condition affects approximately 2 or 3 out of every 100 children. It is estimated that as many as three percent of children in the U.S. have some degree of vision impairment due to amblyopia. Unless it is successfully treated in early childhood, amblyopia usually persists into adulthood, and is the most common cause of monocular (one eye) visual impairment among children and young and middle-aged adults.

Conjunctivitis

Conjunctivitis, inflammation of the conjunctiva, a mucous membrane that lines the inner surface of the eyelids and joins with the cornea of the eyeball. Conjunctivitis may be caused by infection, allergy, or injury and is marked by redness and swelling, accompanied by a feeling of roughness as the membrane passes over the exposed surface of the eyeball. The eye may be sensitive to light; in more severe cases a mucoid sticky fluid, or even pus, may be discharged, depending on the cause of the infection.

The acute form of conjunctivitis is commonly called pink eye. It can be caused by either bacterial or viral infection and is often epidemic. Conjunctivitis caused by exposure of the eye to a welding arc or other source of ultraviolet rays is called flash kerato-conjunctivitis.

Most cases of bacterial conjunctivitis are treated successfully with antibiotics and sulfonamides. Viral conjunctivitis usually lasts about two weeks; treatment may be necessary in cases that involve complications.

Floaters

Floaters are tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of your eye. You can often see them when looking at a plain background, like a blank wall or blue sky. Floaters may look like specks, strands, webs, or other shapes. Actually, what you are seeing are the shadows of floaters cast on the retina , the light-sensitive part of the eye. If a spot or shadowy shape passes in front of your field of vision or to the side, you are seeing a floater. Because they are inside your eye, they move with your eyes when you try to see them. Most spots and eye floaters are merely annoying but harmless when they temporarily enter the field of vision, and many fade over time. People sometimes are interested in surgery to remove floaters, but doctors are only willing to perform such surgery in rare instances.

Retinal detachment

Retinal detachment is a separation of the light-sensitive membrane in the back of the eye (the retina ) from its supporting layers. The retina is a transparent membrane at the back of the eye, which processes the images that are focused on it by the cornea and the lens. Retinal detachments are often associated with a tear or hole in the retina through which the internal fluids of the eye may leak. This causes separation of the retina from the underlying tissues. Retinal detachment may be caused by trauma, the aging process, severe diabetes, or an inflammatory disorder, but it frequently occurs spontaneously. During a detachment, bleeding from small retinal blood vessels may cloud the interior of the eye, which is normally filled with vitreous fluid. Central vision becomes severely affected if the macula , the part of the retina responsible for fine vision, becomes detached.

Cataract

Cataract is a condition of the eye which crystalline lens loses its transparency and obstructs the passage of light.  Adult cataracts usually develop with advancing age and may run in families. Cataracts are accelerated by environmental factors, such as smoking or exposure to other toxic substances, or they may develop at any time after an eye injury. Metabolic diseases such as diabetes also greatly increase the risk for cataracts. Certain medications, such as cortisone, can also accelerate cataract formation. Adult cataracts are generally associated with aging. They develop slowly and painlessly with a gradual onset of difficulty with vision. Adult cataracts are classified as immature, mature, and hypermature. A lens that has some remaining clear areas is referred to as an immature cataract. A mature cataract is completely opaque. A hypermature cataract has a liquefied surface that leaks through the capsule and may cause inflammation of other structures in the eye.

Crossed-eyes

Dry Eye Syndrome

Dry eye syndrome is one of the most common problems treated by eye physicians. Over ten million Americans suffer from dry eyes. It is usually caused by a problem with the quality of the tear film that lubricates the eyes. In addition to lubricating the eye, tears are also produced as a reflex response to outside stimulus such as an injury or emotion. However, reflex tears do little to soothe a dry eye, which is why someone with watery eyes may still complain of irritation.

Dry eye syndrome has many causes. One of the most common reasons for dryness is simply the normal aging process. As we grow older, our bodies produce less oil - 60% less at age 65 then at age 18. This is more pronounced in women, who tend to have drier skin then men. The oil deficiency also affects the tear film. Without as much oil to seal the watery layer, the tear film evaporates much faster, leaving dry areas on the cornea.

Many other factors, such as hot, dry or windy climates, high altitudes, air-conditioning and cigarette smoke also cause dry eyes. Many people also find their eyes become irritated when reading or working on a computer. Stopping periodically to rest and blink keeps the eyes more comfortable.

Contact lens wearers may also suffer from dryness because the contacts absorb the tear film, causing proteins to form on the surface of the lens. Certain medications, thyroid conditions, vitamin A deficiency, and diseases such as Parkinson's and Sjogren's can also cause dryness. Women frequently experience problems with dry eyes as they enter menopause because of hormonal changes.

Glaucoma

Glaucoma is the name for a group of diseases that can destroy the optic nerve, the main nerve of the eye. The word glaucoma means "hard eyeball." Any one of the conditions classified as glaucoma can lead to irreversible blindness by damaging the optic nerve. Glaucoma sneaks up on people. There are no symptoms other than loss of vision, which can occur so gradually that many people do not realize it is happening. The first vision loss is usually peripheral vision (what you can see off to the sides when you are looking straight ahead). Even though glaucoma cannot be cured, it can be treated. If it is spotted in its early stages, before any sight is lost, blindness can almost always be prevented. But the longer glaucoma remains untreated, the more vision can be lost. Glaucoma is considered a thief of eyesight. The only way to make sure that it doesn't sneak up is to have regular eye exams.

Maular Degeneration

Age-Related Macular Degeneration (AMD) is a common eye disease of older people. It causes loss of the sharp, central vision needed for many daily tasks that involve looking straight at objects. People with AMD may find it difficult or impossible to drive, read, sew, or recognize faces. Many also have trouble distinguishing colors. It results from an abnormality in a small part of the retina called the macula (MAK-yoo-luh). The retina is a tissue-thin membrane lining the back of the eye. People lose this central vision when macular cells degenerate, or stop working normally. The degeneration and vision loss usually occurs slowly, over a period of years. People with AMD retain peripheral vision, or side vision.