Vision Library


Age Related Macular Degeneration


CIBA VISION does not currently offer any treatments for Age Related Macular Degeneration (AMD). Please visit our sister company Novartis Ophthalmics for more detailed information and treatments for AMD. Or visit Novartis Ophthalmics' specific AMD website at www.visudyne.com.

Astigmatism


If you experience a distortion or blurring of images at all distances – nearby as well as far away – you may have astigmatism. Even if your vision is fairly sharp, headache, fatigue, squinting and eye discomfort or irritation may indicate a slight degree of astigmatism. A thorough eye examination, including tests of near vision, distant vision and vision clarity, can determine if astigmatism is present.

Astigmatism is not a disease nor does it mean that you have "bad eyes." It simply means that you have a variation or disturbance in the shape of your cornea.

How is it diagnosed?
Astigmatism is diagnosed in the course of a thorough eye examination. If the degree of astigmatism is slight and no other vision correction such as nearsightedness or farsightedness is present, corrective lenses may not be needed. If the degree of astigmatism is great enough to cause eyestrain, headache or distortion of vision, prescription lenses will be needed for clear and comfortable vision.

How is it treated?
Your eye care professional will recommend corrective eyewear, contact lenses or spectacles, to help the eye direct light in a more effective manner.

The corrective lenses needed when astigmatism is present are called Toric lenses and have an additional power element called a cylinder. They have greater light-bending power in one axis than in others. CIBA VISION offers many Toric contact lenses for the correction of astigmatism – Focus® Toric, Focus® DAILIES® Toric, FreshLook® Toric, FreshLook ColorBlends® Toric and others.

Your eye care professional will perform precise tests during your eye examination to determine the ideal lens prescription.

What causes astigmatism?

Astigmatism usually occurs when the front surface of the eye, the cornea, has an irregular curvature. Normally the cornea is smooth and equally curved in all directions and light entering the cornea is focused equally on all planes, or in all directions. In astigmatism, the front surface of the cornea is curved more in one direction than in the other. With the cornea's shape more like that of an American football or rugby ball than a basketball, the light hitting the more curved surface comes to a focus before that which enters the eye through the less curved surface. Thus, the light is focused clearly along one plane, but is blurred along the other so only part of an image can be in focus at any time.

This abnormality may result in vision that is much like looking into a distorted, wavy mirror. The distortion results because of an inability of the eye to focus light rays to a point.

How does astigmatism affect sight?
The crystal clear cornea is situated at the very front surface of the eye and enables light to enter the eyeball. The cornea accomplishes about four-fifths of the refractive work needed for clear vision, bending light rays toward one another into a point. The lens, located behind the cornea, further refines the refractive work begun by the cornea and directs the point of light toward a precise location on the retina, known as the fovea. If light is not focused into a fine point on the fovea, the image that reaches the retina cannot be clearly transmitted to the brain.

When astigmatism is present, the surface of the cornea is distorted instead of being spherical. It is unable to focus light rays entering the eye into the fine point needed for clear vision. At any time, only small proportions of the rays are focused and the remainder is not, so that the image formed is always blurred. Usually, astigmatism causes blurred vision at all distances.

Why are corneas shaped differently?
Not all corneas are perfectly curved, just as sets of teeth are seldom perfectly aligned. The degree of variation determines whether or not you will need corrective eyewear. If the corneal surface has a high degree of variation in its curvature, light refraction may be impaired to the degree that corrective lenses are needed to help focus light rays better.

The exact reason for differences in corneal shape remains unknown, but the tendency to develop astigmatism is inherited. For that reason, some people are more prone to develop astigmatism than others.

Who develops astigmatism?
Astigmatism is very common. Some experts believe that almost everyone has a degree of astigmatism, often from birth, which may remain the same throughout life.

Of interest to parents and those who work with children, astigmatism may contribute to poor schoolwork but is often not detected during routine eye screening in schools.

Does astigmatism get worse?
Astigmatism may increase slowly. Regular eye care can help to insure that proper vision is maintained.
How will astigmatism affect my lifestyle?

You may have to adjust to wearing contact lenses or eyeglasses if you do not wear them now. Other than that, astigmatism probably will not significantly affect your lifestyle at all.

Cataracts

A cataract is a clouding or darkening that develops in the normally clear lens of the eye. This prevents the lens from properly focusing light on the retina at the back of the eye, resulting in a loss of vision. A cataract is not a film that grows over the surface of the eye.

Corneal Oxygen Deficiency

Good vision requires a healthy cornea and to work properly, the cornea needs a high level of oxygen. When the cornea does not receive enough oxygen, corneal oxygen deficiency (hypoxia) occurs and the eye may become stressed.

A primary cause of corneal oxygen deficiency is wearing low oxygen transmissible soft contact lenses. The contact lens acts as a barrier between the eye and the oxygen that the eye needs. Corneal oxygen deficiency is a contributing factor in many adverse corneal responses.

Corneal oxygen deficiency may be reduced by changing to contact lenses containing materials that allow more oxygen to reach the eye. State-of-the art “breathable” contact lenses, which are made with materials that allow greater amounts of oxygen to pass through the lens and reach the eye, are designed to decrease corneal oxygen deficiency. O2OPTIX and NIGHT & DAY contact lenses are made with a revolutionary silicone hydrogel technology that allows more oxygen to reach the eye than traditional soft contact lenses.

Double Vision

If you see two of whatever you are looking at simultaneously, you may have a condition known as double vision, also referred to as diplopia. Double and blurred vision are often thought to be the same, but they are not. In blurred vision, a single image appears unclear. In double vision, two images are seen at the same time, creating understandable confusion for anyone who has it.

Dry, Irritated Eye

If your eyes sting, itch or burn, you may be experiencing the common signs of "dry eye." A feeling of something foreign within the eye or general discomfort may also signal dry eye.

Eye Allergies

The most common types of ocular (eye) allergies are seasonal and perennial (year round) allergic conjunctivitis. Seasonal allergic conjunctivitis (hay fever conjunctivitis) is the more common type, accounting for the majority of allergic conjunctivitis cases.

If you wear contact lenses and suffer from dry, itchy eyes, ask your doctor about Focus® DAILIES®. Even if you are non-allergic, you can develop red, irritated eyes when scratchy pollen builds up on your lenses. Daily disposable lenses allow you to discard the lens before airborne irritants get a chance to build up. If you are presbyopic ("over-40," loss of near vision), CIBA VISION also offers Focus® Progressives and Focus® DAILIES® Progressives multi-focal lenses.

Farsightedness

If you can see objects at a distance clearly but have trouble focusing well on objects close up, you may be farsighted.

Your eye care practitioner may refer to farsightedness by its medical names, hypermetropia or hyperopia. Hyperopia causes the eyes to exert extra effort to see close up. After viewing nearby objects for an extended period, you may experience blurred vision, headaches and eyestrain. Children who are farsighted may find reading difficult.

Hyperopia is not a disease, nor does it mean that you have "bad eyes." It simply means that you have a variation in the shape of your eyeball. The degree of variation will determine whether or not you will need corrective lenses.

What causes farsightedness?
Hyperopia most commonly occurs because the eyeball is too short; that is, shorter from front to back than is normal. In some cases, the cornea having too little curvature may cause hyperopia.

Exactly why eyeball shape varies is not known, but the tendency for farsightedness is inherited. Other factors may be involved too, but to a lesser degree than heredity.

How does farsightedness affect sight?
Our ability to "see" starts when light enters the eye through the cornea. The shape of the cornea, lens and eyeball help bend (refract) light rays in such a manner that light is focused into a point precisely on the retina.

If, as in farsightedness, the eyeball is too short, the "point of light" focuses on a location behind the retina, instead of on the correct area of the retina, known as the fovea. As a result, at the point on the retina where a fine point of light should be focused, there is instead a disk-shaped area of light. Since light is not focused when it hits the retina, vision is blurred.

Convex lenses are prescribed to bend light rays more sharply and bring them to focus on the retina.

Who is affected by farsightedness?
Many people have a degree of farsightedness, yet it is only a problem if it significantly affects your ability to see well or causes headaches or eyestrain.
How is it diagnosed?
Hyperopia is seldom diagnosed in school eye-screening tests, which typically test only the ability to see objects at a distance. A comprehensive eye health examination that checks both near and far vision is necessary to diagnose farsightedness.
How is it farsightedness treated?

Convex lenses – eyeglasses or contact lenses – are usually prescribed. They bend light rays more sharply and bring the rays into focus on the retina.

To determine the best avenue of treatment, your eye care professional may ask a number of questions about your lifestyle, occupation, daily activities and general health status. For instance, you may be asked whether or not you frequently need near vision. Providing candid, considered answers to the questions and working with your eye care professional will help assure that your corrective lenses contribute to clear sight and general comfort.

A comprehensive eye examination at the recommended intervals will ensure that minor changes in vision are diagnosed and treated so that your vision will remain as clear and comfortable as possible.

How will hyperopia affect your lifestyle?
If glasses or contact lenses are prescribed, it may take a few days to adjust to them. After that, farsightedness probably will not significantly affect your lifestyle.

Glaucoma

Glaucoma can steal your vision gradually and without you noticing, yet glaucoma is a serious disease that can result in severe loss of sight. The best defense against glaucoma is regular eye examinations. Glaucoma most often strikes people over age 50, but it is recommended that during adult life everyone be tested at least every two years.

Nearsightedness

If you can see objects nearby with no problem, but reading road signs or making out the writing on the board at school is more difficult, you may be near- or shortsighted.

Your eye care professional may refer to the condition as myopia, a term that comes from a Greek word meaning "closed eyes." Use of the word "myopia" for this condition may have grown out of one of the main indications of nearsightedness: Squinting to see distant objects clearly.

Myopia is not a disease, nor does it mean that you have "bad eyes." It simply refers to a variation in the shape of your eyeball. The degree of variation determines whether or not you will need corrective eyewear.

What causes nearsightedness?
Myopia most often occurs because the eyeball is too long, rather than the normal, more rounded shape. Another less frequent cause of myopia is that the cornea, the eye's clear outer window, is too curved. There is some evidence that nearsightedness may also be caused by too much close vision work.
How does myopia affect sight?
Our ability to "see" starts when light enters the eye through the cornea. The shape of the cornea, lens and eyeball help bend (refract) light rays in such a manner that light is focused into a point precisely on the retina.

In contrast, if you are nearsighted, the light rays from a distant point are focused at a place in front of the retina. As the light will only be focused in that one place, by the time it reaches the retina it will have "defocused" again, forming a blurred image.

Who is affected by nearsightedness?
Myopia usually occurs between the ages of eight to 12 years. Since the eyes continue to grow during childhood, nearsightedness almost always occurs before the age of 20. Often, the degree of myopia increases as the body grows rapidly, and then levels off in adulthood. During the years of rapid growth, frequent changes in prescription eyewear may be needed to maintain clear vision.
How is myopia diagnosed?
Myopia is often suspected when a teacher notices a child squinting to see a blackboard or a child performs poorly during a routine eye screening. Further examination will reveal the degree of the problem.

A comprehensive eye health examination will detect myopia. Periodic examinations should follow after myopia has been discovered to determine whether the condition is changing, and whether a change in prescriptive eyewear is needed. Eye exams also help to ensure that vision impairments do not interfere with daily activities.

How is myopia treated?
Corrective concave lenses are prescribed to help focus light more precisely on the retina, where a clear image will be formed.

Depending on the degree of myopia, glasses or contact lenses may be needed all of the time for clear vision.

How will nearsightedness affect my lifestyle?
If glasses or contact lenses are prescribed, it may take you a few days to adjust to them. After that, nearsightedness will probably not significantly affect your lifestyle. However, more severely nearsighted individuals may find the condition limits their choice of occupation in some cases.
Nearsightedness in children
School-age children may have vision problems ranging from mild to severe. When problems are suspected, it is important that the child have a comprehensive eye health examination to determine the nature of the problem and to rule out serious eye diseases. When vision conditions are treated properly, the child will enjoy the best possible sight.

To help a child cope with nearsightedness

  • Avoid referring to the child's eyes as "bad eyes;" instead, tell the child that his or her eyes just bend light differently and corrective lenses are needed to help focus light rays.
  • Use illustrations and simple explanations to help the child understand how a differently shaped eyeball may result in his or her nearsightedness.
  • Consider contact lenses as an option.
  • Do not restrict the child's activities because of poor vision.
  • Include the child in discussions about his or her eyesight.
  • Encourage the child to verbalize concerns about the adjustment to rapidly changing vision.

Presbyopia - the "over 40" loss of near vision

Hold the book up close and the words appear blurred. Push the book farther away, and the words snap back into sharp focus.

That's how most of us first recognize a condition that eye care professionals call presbyopia, a name derived from Greek words meaning "old eye." Eye fatigue or headaches when doing close work, such as sewing, knitting or painting, are also common symptoms. Because it is associated with aging, presbyopia is often met with a groan – and an expectation that reading glasses or bifocals are inevitable. Until recently this was true, however CIBA VISION's Focus® Progressives and new Focus® DAILIES® Progressives soft contact lenses can provide clear and comfortable vision at all distances without the hassles, vision jumps and distortions typical of bifocals or reading glasses for individuals with presbyopia.

What causes presbyopia?
As we age, body tissues normally lose their elasticity. As skin ages, it becomes less elastic, and we develop wrinkles. Similarly, as the lenses in our eyes lose some of their elasticity, they lose some of their ability to change focus for different distances. The loss is gradual. Long before we become aware that seeing close up is becoming more difficult, the lenses in our eyes have begun losing their ability to change shape to help focus light rays. Only when the loss of elasticity impairs our vision to a noticeable degree do we recognize the change.
How does the loss of elasticity affect sight?
Our ability to "see" starts when light enters the eye through the cornea. The shape of the cornea, lens, and eyeball help bend (refract) light rays in such a manner that light is focused into a point precisely on the retina.

The crystalline lens plays a key role in focusing light on the retina. When we are young, the lens is flexible. With the help of tiny ciliary muscles, it changes shape, or accommodates, for both near and distant objects by bending or flattening out to help focus light rays. As we age, the lens becomes stiffer. Changing shape becomes more difficult. Not only does focusing on near objects become more difficult, the eye also is unable to adjust as quickly to rapid changes in focus on near and distant objects.

When does it occur?
The flexibility of the lens begins to decrease in youth. The age at which presbyopia is first noticed varies, but it usually begins to interfere with near vision in the mid to late 40's. Presbyopia affects everyone and there is no known prevention for it.
How is the problem diagnosed?
An accurate, thorough description of symptoms and a comprehensive eye health examination, including a testing of the quality of your near vision, are necessary to diagnose presbyopia.
How is presbyopia treated?
Traditionally, eye care professionals prescribe bifocal spectacles or reading glasses to help the eye accommodate for close-up work. However, soft contact lenses such as CIBA VISION's Focus® Progressives are increasing in popularity as an exciting alternative for people with presbyopia. CIBA VISION also offers Focus® DAILIES® Progressives – the first daily disposable contact lens for the correction of presbyopia
What lens option will work best for me?
Your eye care professional may ask a number of questions to help determine the best avenue of treatment. You may be asked to describe your usual lifestyle or daily activities, and from this your practitioner will be able to recommend a solution most suited to your needs.
Once my vision is corrected for presbyopia, will I require frequent lens changes?
Presbyopia is a gradual change, happening over a number of years, so your prescription will need to be updated periodically. Changes are best made at your regular eye examination rather than after the need for change starts to cause you difficulties.

Spots & Floaters

Do you occasionally see specks or threadlike strands drifting across your field of vision? Then, when you try to look at them, do they seem to dart away? If so, you're seeing what eye care practitioners call spots or floaters.

While almost everyone sees a few spots at one time or another, they can occur more frequently and become more noticeable as you grow older. If you notice a sudden change in the number or size of spots, you should contact your eye practitioner right away so you can be sure they are not the result of a more serious problem.

What are spots or floaters?
Spots are small, semi-transparent or cloudy specks or particles within the eye that become noticeable when they fall within the line of sight. They may also appear with flashes of light.
What causes them?
The inner part of your eye is made up of a clear, jelly-like fluid known as the vitreous. Occasionally, small flecks of protein and other matter become trapped during the formation of the eye before birth and remain in the eye's vitreous body, resulting in the spots.

When flashes of light occur, causing spots to become noticeable, it can be a result of the jelly-like vitreous shrinking and pulling on the retina. This tugging action stimulates the retinal receptor cells that "fire," causing the perception of light flashes.

Can these spots cause blindness?
Most spots are normal and rarely cause blindness. But spots can indicate more serious problems. If you notice a change in the number and size of spots, a comprehensive eye examination is in order to determine the cause.

On rare occasions, vitreous detachment can cause small tears or holes in the retina. The damaged part of the retina subsequently does not work properly and a blind or blurred spot in vision results. If untreated, retinal tears or holes can continue to worsen and severe vision loss can result if the retina becomes detached.

How are spots diagnosed?
In a comprehensive eye examination, your eye care practitioner will look into your eyes with special instruments that allow an examination of the health of the inside of your eyes and possible observation of the spots.

This is often done after the practitioner puts special drops in your eyes to make the pupils larger (called dilation) to allow a larger view of the inside of your eyes. These procedures provide your eye practitioner with relevant information to detect spots.

How are spots treated?
While flashes and floaters are normally not serious or treatable, they can be symptoms or signs of either vitreous or retinal detachment. In either of these cases, treatment with lasers and/or surgical intervention may be necessary to preserve your vision. If you notice a sudden increase or change in the number and type of spots and floaters, contact your eye care practitioner immediately.