Vision
problems

What is it?

Myopia occurs when the eye is effectively too long, meaning the distance between the cornea and the retina is too great. Light entering the eye is therefore focused before it reaches the retina, which causes blurred vision.

In some cases, it can be due to the shape of the cornea or the thickness of the lens inside the eye.

Hereditary factors are currently thought to be the most important. You are more likely to develop myopia if one of your parents has it.

Signs and symptoms

A person with myopia can see things close up fairly clearly, for example when reading. But for tasks that need distance vision, such as driving or watching television, their vision is blurred.

People with uncorrected myopia often also have symptoms such as headaches or eye strain when they try to focus on distant objects. In children, myopia can lead to other eye problems early in life, such as a squint (strabismus) or a lazy eye.

In some cases, people with more severe myopia are also more likely to develop conditions such as glaucoma, early cataract and retinal detachment.

Treatments

Myopia is usually detected fairly early in life, during an eye test that checks your vision and examines your eyes in detail.

There is no cure for myopia as such, but it can easily be corrected with glasses or contact lenses of negative power (the lens is concave, which improves focusing). Another technique is called orthokeratology: contact lenses that you wear at night to reshape the cornea for the following day, so that it focuses better.

You may need to wear your correction all the time, or only when you need sharp distance vision, for example for driving or watching television.

For children who show early signs of myopia, an approach called “myopia management” aims to limit its progression by various methods. These include specialised contact lenses or glasses. Eye drops are also the subject of early research.

Adults can also have laser eye surgery or phakic lens implants (intraocular lenses) to correct their myopia.

The best way to choose the option that suits your way of life is to discuss the different treatments with your ophthalmologist.

What is it?

In normal vision, an image is sharply focused on the surface of the retina. In hyperopic patients, the cornea does not refract light correctly, so the focal point lies behind the retina. This can be caused by an eyeball that is too short or a cornea that is too flat.

The causes are not always clear, and hyperopia is very often inherited from the parents.

Age-related long-sightedness is called presbyopia.

Symptoms

Hyperopia makes close-up tasks difficult and more tiring for the eyes. Often the effort becomes too much, and reading or using a phone (sometimes even a computer) becomes blurred. People sometimes squint or hold things at arm's length to try to see clearly.

Treatments

Hyperopia can usually be corrected easily with glasses. This is probably the most common way of treating it, and your glasses prescription will show a higher lens power. Because hyperopia can increase with age (or be less well compensated by accommodation), the power of your correction may need to be increased as you get older.

Hyperopia can also be corrected with contact lenses. People with hyperopia usually wear convex contact lenses to obtain normal vision.

For some people, laser eye surgery can be an option to correct their hyperopia. The best way to choose the option that suits your way of life is to discuss the different treatments with your ophthalmologist.

What is it?

Astigmatism occurs when the cornea or the lens is shaped more like a rugby ball than a football. The eye then focuses light at two separate points on the retina, which can make vision blurred and distorted.

Astigmatism is usually present from birth, and it is common in premature or low-birth-weight babies. It can also develop later in life, as part of an eye condition such as keratoconus, or after an injury or eye surgery.

Symptoms

Astigmatism can cause blurred vision, a squint, headaches and eye strain, which you may notice after using a computer for a while.

Astigmatism is usually associated with myopia and hyperopia. Astigmatism in one eye can lead to amblyopia (lazy eye), meaning that vision does not develop properly. Amblyopia needs to be detected early so that it can be treated.

Treatment

Astigmatism can be treated with prescription glasses or contact lenses, or with surgery.

The best way to choose the option that suits your way of life is to discuss the different treatments with your ophthalmologist.

What is it?

Presbyopia is a vision defect that appears with age. Usually at around 40 to 45, it becomes hard to see sharply up close. It sets in naturally as the lens and its capsule age. The lens, which is what allows the eye to accommodate (adjust its focus), loses flexibility and elasticity. In practice, a person with presbyopia has difficulty with near vision, while distance vision is not affected.

With age, the quality of vision naturally declines. The lens deteriorates and struggles to focus a close-up image; the eye gradually loses its power of accommodation. Age is therefore the main factor in presbyopia. This loss of accommodation is inevitable: it cannot be halted or stopped. Presbyopia progresses over about fifteen years, then stabilises at around 55 to 60.

Symptoms

If you are in your forties, it may concern you. The first signs very often appear when reading. You can no longer read up close and hold your book or other objects further away to see them better. For a patient whose vision is otherwise good, presbyopia shows up as difficulty with near vision, particularly with small print or the details of a picture, and in dim light.

People with myopia will notice presbyopia later than people with hyperopia. In a myopic eye, the image falls in front of the retina, which compensates for presbyopia when the myopia is not corrected. A hyperopic eye, on the other hand, projects the image behind the retina, as presbyopia does, which accentuates the problem. The onset of presbyopia is therefore very hard on a patient who is already hyperopic, all the more so as it generally comes earlier. Near and distance vision both deteriorate quickly from the age of 40.

Treatment

Presbyopia is linked to the ageing of the lens. The ciliary muscle still does its job and contracts, but the lens can no longer thicken enough to bring the light rays together correctly on the retina. So presbyopia does not come from a muscle that could be exercised to make it stronger: it comes from the lens wearing out. At present, no technique or treatment can prevent or delay presbyopia.

A check-up is recommended every 5 years before 45, then every 2 to 3 years after 45, and every 2 years from around 60.

As a general rule, seeing an ophthalmologist regularly is strongly advised. Only an ophthalmologist can detect a possible eye disease, such as the onset of glaucoma or cataract. If you know of a family history of eye disease, extra vigilance is recommended.

Presbyopia can be corrected with glasses fitted with so-called spherical lenses, which give symmetrical vision. A person with presbyopia can wear this type of glasses for reading or for screen work.

If a person with presbyopia also has myopia or hyperopia (or even if no distance correction is needed), progressive lenses (varifocals) are one way of correcting both conditions. This person can also consider wearing contact lenses for distance vision, with glasses on top to correct the presbyopia. There are also multifocal contact lenses that correct both distance and near vision.

Lastly, presbyopia can be treated with laser surgery. Multifocal correction can be part of an overall plan to improve vision, allowing the person with presbyopia to do without glasses completely or partly. Strictly speaking, this does not treat presbyopia: the aim is comfortable vision without glasses for everyday activities. Several strategies are possible, depending on the patient's expectations and their other vision defects (myopia, hyperopia, astigmatism). The patient “tries out” these options beforehand with trial contact lenses.