Contact Lenses Can Help Correct Common Vision Problems like Astigmatism and Presbyopia

• Astigmatism
• Corneal Oxygen Deficiency
• Dry Eye
• Eye Allergies
• Farsightedness
• Nearsightedness
• Presbyopia (“over 40” loss of near vision)

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 optics of your eyes.

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, typically the front surface of the cornea is curved more in one direction than in the other. One way to think of this is that with astigmatism, the cornea's shape is more like that of an American football or rugby ball than a basketball. The light passing through the more curved surface comes to a focus before the light passing 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 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 several toric contact lenses for the correction of astigmatism, including AIR OPTIX^® for ASTIGMATISM monthly contact lenses, DAILIES^® Toric daily disposable contact lenses and FreshLook^® ColorBlends^® Toric contact lenses.

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

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.

For important information on AIR OPTIX^® for ASTIGMATISM contact lenses, click here.
FreshLook^® contact lenses: Contact lenses, even if worn for cosmetic reasons, are medical devices that must only be worn under the prescription, direction and supervision of an eye care professional. Serious eye health problems may occur as a result of sharing contact lenses.

Does astigmatism get worse?

Astigmatism may increase slowly. Regular eye care can help to ensure that proper vision correction 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.

Corneal Oxygen Deficiency

Good vision requires a healthy cornea. 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 stressed¹.

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 may be reduced by changing to contact lenses containing materials that allow more oxygen to reach the eye. State–of–the art “breathable” silicone hyrdrogel 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. All AIR OPTIX^® brand contact lenses are made with silicone hydrogel materials that allow more oxygen to reach the eye than traditional soft contact lenses.

Dry, Irritated Eye

If you wear contact lenses and suffer from dry, itchy eyes with contact lens wear, talk to your doctor about the benefits of silicone hydrogel or daily disposable contact lenses.

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.

The use of daily disposable lenses, such as DAILIES^® AquaComfort Plus^® contact lenses, helps reduce ocular allergy symptoms by eliminating exposure to lens care product preservatives and minimizing exposure to allergens that can build up on lenses that are reused over a period of time.

For important information on AIR OPTIX^® NIGHT & DAY^® AQUA contact lenses, click here.
Ask your eye care professional for important wear, care and safety information for DAILIES^® AquaComfort Plus^® contact lenses.
¹ Fonn D, Sweeney D, Holden B, Cavanagh D. Corneal Oxygen Deficiency. Eye & Contact Lens. 31(1): 23–27, 2005.

Farsightedness/Hyperopia

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 professional may refer to farsightedness by its medical names, hypermetropia or hyperopia. Farsightedness 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 or have eye strain even though they pass normal vision screening tests.

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

What causes farsightedness?

For the focus of the eye to be perfect, the optical power of the cornea must be perfectly suited with the length of the eyeball. Farsightedness 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 farsightedness.

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 and crystalline lens help bend (refract) light rays in such a manner that light is focused into a point precisely on the back of the eye.

If, as in farsightedness, the eyeball is too short, the light focuses on a location behind the retina, instead of on the retina at the back of the eye. 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?

Farsightedness 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 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 comfort.

A comprehensive eye examination at the recommended intervals will ensure that minor changes in vision are diagnosed and corrected so that your vision will remain as clear and comfortable as possible. All existing CIBA VISION^® contact lenses are available for farsightedness correction.

How will farsightedness 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.

Nearsightedness/Myopia

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 nearsighted.

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 focus of your eyes. The degree of variation determines whether or not you will need corrective eyewear.

What causes nearsightedness?

Although historically an excess of near work (i.e. reading) has been considered a risk factor for the development of myopia, the most recent evidence indicates that the bigger factor is the time spent doing outdoor activities, which appears to protect against development of myopia¹.

¹ Mutti DO. Hereditary and Environmental Contributions to Emmetropization and Myopia. Opt Vis Sci 2010;87.

How does myopia affect sight?

Our ability to “see” starts when light enters the eye through the cornea. The shape of the cornea and crystalline lens 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 often starts between the ages of 8 to 14 years¹. The eyes continue to grow during childhood and myopia most often occurs before the age of 20. Often the degree of myopia levels off in adulthood, although some progression is common through the twenties².

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 prescription eyewear is needed.

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. All existing CIBA VISION^® contact lenses are available for the correction of nearsightedness.

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.

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.

¹ Zadnik K. Myopia development in childhood. Opt Vis Sci 1997;74(8):603–8.
² Bullimore M, Jones L, Moeschberger M, et al. A Retrospective Study of Myopia Progression in Adult Contact Lens Wearers. Invest Ophthalmol Vis Sci 2002;43:2110–3.

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 come 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 with AIR OPTIX^® AQUA MULTIFOCAL monthly replacement contact lenses, clear vision at all distances is possible for those with presbyopia. CIBA VISION^® also offers DAILIES^® Progressives contact lenses — a daily disposable contact lens for patients with presbyopia.

What causes presbyopia?

As we get older, the lenses in our eyes lose some of their elasticity, and with this 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 and crystalline lens 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 the ciliary muscle, 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 decreases gradually throughout life. The age at which presbyopia is first noticed varies, but it usually begins to interfere with near vision in the early 40s. Presbyopia affects everyone and there is no known prevention for it.

For important information on AIR OPTIX^® AQUA MULTIFOCAL contact lenses, click here.

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?

Historically, eye care professionals prescribed bifocal spectacles or reading glasses to help the eye accommodate for close-up work. However, soft contact lenses such as AIR OPTIX^® AQUA MULTIFOCAL monthly replacement contact lenses are an exciting alternative for people with presbyopia. CIBA VISION^® also offers DAILIES^® Progressives contact lenses — a 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 option for correcting your vision. You may be asked to describe your usual lifestyle or daily activities, and from this your professional will be able to recommend a solution most suited to your needs.

Once my vision is corrected for presbyopia, will I require frequent prescription 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.

For important information on AIR OPTIX^® AQUA MULTIFOCAL contact lenses, click here.