Farsightedness (hyperopia)

Children and teenagers usually don't notice farsightedness at all because their eyes can normally compensate for it well. But that means that the muscle in the middle layer of the eye that focuses the eye on near or distant objects (ciliary muscle) is constantly tensed. Close-up vision in particular, like reading a book, can then put too much strain on the eyes and cause various symptoms:

• Headaches
• Quickly tiring eyes
• Aching eyes
• Stinging eyes
• Conjunctivitis

As we get older, though, our eyes can no longer compensate for the farsightedness as well because the ciliary muscle gets weaker. That’s why nearby things become increasingly blurry. From about the age of 30, many farsighted people then have to hold a newspaper further away from them to be able to read it properly.

That could also happen sooner, depending on how severe your farsightedness is. Or your vision may not only be blurry close up, but also at middle distance. The severity of the farsightedness is measured in diopters. The higher the diopter value is over zero, the more severe the farsightedness.

The light rays that enter our eye are refracted by the cornea and the lens. They are then directed so that they all meet (converge) at a single point, known as the focal point (focus). If this point lies directly on the retina inside the eyeball, we see a clear image. The retina is where our photoreceptors are. There are very many photoreceptors on the center part of the retina known as the macula, where our vision is the sharpest.

The closer an object is, the more the light rays it reflects that have to be refracted to converge on the retina. That is where the ciliary muscle comes in – it contracts to change the shape of the lens. That process is called accommodation. In farsighted eyes, the shape of the lens has to be changed more than in normal eyes. There are two possible reasons for that:

• The eyeball is too short (axial hyperopia): If the eyeball is unusually short, the distance between the lens and the retina is also shorter than normal. For the light rays to converge on the retina, they have to be refracted more. People with short eyeballs are usually born with them, and it’s thought they are hereditary. This is the most common cause of farsightedness.
• Low refractive power of the eye (refractive hyperopia): In rarer cases, the eyeball is normal length, but the cornea or the lens don’t refract the light enough. That can happen if the lens has been shifted by an injury or a tumor, for instance.

If the light is not refracted enough, the focal point is no longer on the retina but behind it, so no clear image can be produced. Close-up vision is then especially blurred.

Almost all children are born with slight farsightedness, but it usually doesn’t cause any problems and often goes away in the first years of life. It is estimated that about 25% of adults in Germany are farsighted.

Farsightedness gets more and more noticeable as you grow older. That’s because the eye gets worse at compensating for it, but the actual severity of the farsightedness, the diopter number, usually changes only a little or not at all.

Near vision can get even worse if age-related farsightedness also develops from the age of about 40. Farsighted people then usually need reading glasses at a younger age.

Severe farsightedness can cause you to squint or look cross eyed (also referred to as "strabismus"). That’s because the ciliary muscle is constantly tensed to to have the eye adjusted properly for close vision. It is perfectly normal for your eyeball to turn slightly towards the nose when you are looking at something close to you – but this happens constantly if you are farsighted. This effect is often so minor that it goes unnoticed (“microsquint”). But it can lead to what is known as “lazy eye” (amblyopia) in children. Squinting causes each eye to generate a different image. The brain then blocks the image from one eye, which affects the child's visual development. Amblyopia in children can normally be improved by wearing glasses or covering the stronger eye with a eye patch for certain periods.

Farsighted people may also develop acute angle-closure glaucoma. The ciliary muscle has then become so thick from constant use that the fluid between the cornea and the lens (aqueous humor) can no longer drain properly. That drastically increases the pressure inside the eye ( intraocular pressure) and damages the optic nerve. Symptoms of acute angle-closure glaucoma can be sudden, severe eye pain and reddening, headaches, nausea and vomiting, and sometimes also impaired vision.

Your eye doctor (ophthalmologist) or optician can diagnose farsightedness by doing various tests. Eye charts are used first to see how well you can still see things as they get smaller and smaller (visual acuity). Special devices are then used to check your eyes’ refractive power, that is to say how severe the refractive error is.

Another eye test is usually done afterwards. You then have to look through different strengths of lenses and say when you can best see the objects on the eye chart. This eye test isn’t possible with people who aren’t able to communicate well enough, such as very young children.

Eye drops that paralyze the ciliary muscle may be needed for the examination, especially in children. They stop the eyes from adjusting to the different distances and giving unreliable results. That makes it possible to measure the extent of farsightedness more precisely. Because the effect of the eyed drops can last a while, your vision will be blurry and you will be very sensitive to light for a few hours after.

Eye doctors sometimes carry out additional eye examinations. For example, they can use ophthalmoscope (or funduscope) to look at the back of the inside of the eyeball (ocular fundus), which is where the retina is found. That can be important if you have other medical conditions like high blood pressure or diabetes that can cause changes there.

Simple eye tests are part of regular check-ups for children. Some pediatricians can also check the eyes’ refractive power using special devices. If there are any abnormalities, the doctor can refer the child to a specialist for more thorough examinations.

People who work with screens must be offered regular eye examinations with a company doctor by their employer.

Farsightedness is treated if the eye can’t compensate on its own, or if the farsightedness is causing problems. Glasses are the simplest aid. They balance out the eyes’ refractive error so that you can see clearly again. Contact lenses are an alternative.

It is not clear whether wearing glasses can prevent squint or amblyopia in children.

Farsightedness in adults can sometimes be corrected with surgery. That typically involves using a laser to increase the curvature of the cornea. Ideally, you will not need to wear glasses or contact lenses after you've had surgery. But procedures like that aren't possible for very severe farsightedness or if you have other medical conditions like wet macular degeneration. There is also a risk of things like vision problems or infections, and the surgery is normally not covered by public health insurers in Germany (and many other countries).

Children with poor eyesight because of farsightedness who don’t wear glasses or contacts might struggle at school. That’s what studies of school children with untreated farsightedness suggest. This is because children find it more difficult to read books or exercise sheets, meaning they might not learn so well. But their school performance seems to get better if they wear glasses.

If the farsightedness is corrected enough, it doesn’t usually cause any problems in everyday life. Children in particular might not want to wear glasses for fear of being teased. It can help to involve children in picking out their own glasses so that they can choose ones they like. It is also important for the glasses to be fitted well and sit comfortably.

People usually go to see their eye doctor or pediatrician if they or their child have problems with their eyes. Information about health care in Germany can help you to navigate the German health care system and find a suitable doctor. You can use this list of questions to prepare for your appointment.