Astigmatism: A defect of the eye or of the lens that causes rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image.
Cataracts: A clouding of the lens of the eye or of its surrounding transparent membrane that obstructs the passage of light. One of the most well-known eye diseases is cataracts. Cataracts are a "hazing" of the normally clear lens inside of the eye. A person's lens normally allows light to reach the retina, thus, enabling clear vision. Cataracts reduce vision, just as a dirty windshield diminishes a driver's view of the road. Factors such as nutrition and genetics play a role in cataract formation, but UV exposure is primarily responsible. The clouding of the lens is irreversible, and once the cataracts begin to impair daily activities, the only treatment available is surgical removal. Cataracts are the number one cause of blindness in the world today. Fortunately, cataract surgery is relatively uncomplicated, and has a very high success rate.
Computer Vision Syndrome: Computer vision syndrome (CVS) is characterized by eyestrain associated with prolonged computer use. Symptoms of CVS include eye irritation, such as dry eye; red, itchy, and watery eyes; fatigue, including heaviness of the eyelids or forehead; and difficulty in focusing the eyes. Other symptoms of CVS are headaches, backaches, and muscle spasms.
CVS occurs because a person’s vision is not suited for staring at a computer screen for many hours. Computer screens are made up of pixels or tiny dots, on which the eye can not lock focus. The computer user must therefore focus and refocus to keep the images sharp. This results in receptive stress of the eye muscles. Additionally, after prolonged computer use, the frequency of blinking is decreased, which causes eyes to dry out and to become sore. As a result, the ability to focus diminishes and vision may blur, which causes headaches and neck pain.
Cornea : The cornea is the eye's primary focusing element and when healthy, is composed of transparent, sturdy tissue that allows light to enter the eye without distortion.
Dry Eyes: In dry eye the
tear film on the eye surface loses water because of either decreased tear production or
increased evaporation. And as evaporation continues throughout the day, your eyes feel
drier and drier. The most common cause of dry eye is aging. As we get older we produce
fewer tears, and evaporation increases. Other common causes include contact lens wear,
sun, wind, dry air, reading, computer use and certain medications. Dry eye is seen with
certain diseases such as Sjögen’s syndrome as well. A
functioning tear film is important for maintaining a healthy cornea and
preserving clear vision. The tear film 
is an important source of eye nutrition, waste removal, and
antibacterial action. Dry eye conditions can disrupt the tear film and
compromise corneal health.
Tears can be replaced by using eye drops called artificial tears. These artificial tears replace the moisture that is missing and lubricate the eyes. They temporarily soothe dry eye symptoms. Artificial tears have provided a quick, short-term solution to dry eye. A popular solution today is tear-duct closure, which allows you to retain your own natural tears, This procedure's closure of the tear drainage ducts involves the use of a non-disolvable, yet removable plug that seals the tear duct. This non-surgical procedure can be performed in only a few minutes and is painless.
Excimer Laser : The excimer laser is the actual device that is used in many vision correction procedures. It is a cool laser that changes the shape of the cornea by eliminating tissue.
Farsightedness (Hyperopia): A condition in which visual images come to a focus behind the retina of the eye and vision is better for distant than for near objects.
Glaucoma
: A disease of the
eye, characterized by increased pressure within the eyeball with progressive loss of vision.
Glaucoma causes optic nerve damage and visual field loss. It is caused by a number of
different eye diseases which can affect the eye. Most, but not all of these diseases, are
characterized by elevated intraocular pressure, which is not the disease itself, but the most
important risk factor for the development of glaucoma. The disease strikes without obvious
symptoms. Therefore, the person with glaucoma is usually unaware of it until serious loss
of vision has occurred. In fact, half of those suffering damage from glaucoma do not know it.
Currently, damage from glaucoma cannot be reversed. However, early detection and treatment
of glaucoma can prevent vision impairment and blindness. There are a few conditions related
to this disease which tend to put some people at greater risk. This may apply to you if:
Macular Degeneration : It is the group of diseases that cause sight-sensing cells in the macular zone of the retina to malfunction or lose function. It is thought to have nutritional, genetic, and UV exposure factors in its development. The disease's result is debilitating loss of vital central or detail vision. The brain cleverly learns to compensate and fill in the missing part of the picture in early cases with spotty macular cell damage or dysfunction so that most people only present it to their ophthalmologist when the disease is fairly advanced. Over 13 million people are affected with the disease. In recent years, the public has become increasingly aware of this ocular disease, which goes by many different names. Macular degeneration is rarely present before age 65, but increases to 20% prevalence between ages 75 to 85. It spares peripheral vision, but adversely affects central vision, similar to looking at a clock and seeing all the numbers, but not seeing the clock hands.
Nearsightedness (Myopia): A condition in which the visual images come to a focus in front of the retina of the eye resulting especially in defective vision of distant objects.
Presbyopia : A visual condition which becomes apparent especially in middle age and in which loss of elasticity of the lens of the eye causes defective accommodation and inability to focus sharply for near vision. The "arm's length pose" while reading is a good indication presbyopia is setting in.
Refraction : When the cornea is misshaped and light doesn't focus properly on the retina, the eye has a refractive problem. The three most common refractive errors are: nearsightedness, when you can't see objects far away; farsightedness, when you can't see objects up close; and astigmatism, when you have trouble focusing on any object.
Refractive Surgery : Refractive surgery is the term which describes all of the methods used to surgically correct the curvature of the cornea to restore the focus point on the retina.
Retina : Located at the back of the eye, the retina's photosensitive cells convert light images into electrical impulses for the optic nerve. The optic nerve sends those impulses to the visual part of the brain, where they are interpreted into what we know as "sight"".
Snow-Blindness (Photokeratitis) : Also known as "welder's flash," this is a condition that comes from a brief, but intense exposure to ultraviolet light. The cornea, the outermost clear part of the eye is affected. Symptoms usually include eye pain (sometimes severe,) light sensitivity, tearing, and a sensation that there is something in the eye. These symptoms usually resolve after about a day. This syndrome is caused by part of the UV spectrum called UV-B. Welder's not wearing a welder's mask for eye protection often experience this problem, as well as people with exposure to bright sunlight in combination with freshly fallen snow. Skiers without eye protection on the slopes, or even exposure to the intense glare from the ocean or lakes can lead to this "sunburn" of the eyes.
Ultraviolet (UV) Light : Ultraviolet (UV) light can cause corneal burns and brunescent cataracts. The corneal burn is a short-term health risk, which is a sunburn on the surface of the eye. These burns show up within a few hours of overexposure and are characterized by increased sensitivity, a burning sensation and excessive tearing. The effects apparently are temporary and usually disappear within a day or so. Brunescent cataracts are a long-term health risk, which is the clouding or a pigmentation of the lens within the eye. They are slow to develop, usually occurring over a matter of years, but they are permanent. The clouding affects night vision and also can alter perception of color. Unfortunately, cataract surgery is the only known cure. Eyewear, such as sunglasses, originally was developed to protect eyes from the potentially damaging rays of the sun and flying debris. Eyewear protects your eyes from potentially harmful ultraviolet light. Eyelids will not tan, they will burn. Ultraviolet damage is cumulative and closing your eyes does not protect them from ultraviolet damage.
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