Glasses and contact lenses for farsightedness

The objects around us reflect light rays into our eyes. These rays of light are refracted by the cornea and the lens so that they meet on the inside of the eye at a single focal point. This focal point is usually right on the retina that lines the inside of the eyeball. It converts light rays into nerve signals, and sends them to the brain via the optic nerve. The result is a clear image of what we are looking at.

Farsighted eyes don’t refract the light enough. That means the focus is behind the retina, and the light rays don’t converge on it. The eye can compensate for that on its own when light rays are coming from objects farther away, but not when the light rays are coming from closer objects and the light has to be refracted much more. This means that the resulting image is blurred.

Glasses can refract the light more and ensure that the focus is right on the retina. Then you can see clearly again. To do that, glasses have specially shaped lenses that are curved outwards (convex), making them a little thicker in the middle than at the edge. These types of lenses are sometimes also called plus, convex or converging lenses. How curved the lens needs to be is determined by how severe the farsightedness is. Your eye doctor or optician measures that in units called diopters. The higher the diopter number, the more curved the lenses are.

Glasses are the easiest and most common solution for farsightedness. If the optician has adjusted them properly, you will be able to see clearly. If the refractive power of your eyes changes, you can have news lenses made and put into your existing frame or a new frame.

There are hardly any medical disadvantages to glasses. They can pose an injury risk in certain situations, like if you are hit by a ball during sports that then smashes the glasses. Sports and children’s glasses with particularly strong plastic lenses can prevent that.

Only very few people have an allergic reaction to material components in the frame (eyeglass frame allergy). This contact allergy can cause rashes, swelling or itching on the temples, ears or bridge of the nose.

Glasses can be bothersome in certain situations, like during sports, in the rain, or if they fog up. And some people are less happy with their appearance when wearing glasses, while others use them as a fashion accessory.

Children often find it difficult to regularly wear their glasses, perhaps because wearing glasses can be bothersome when playing. And for some children it's important to have fashionable glasses, because they might be teased otherwise.

Children might be more accepting if they are involved in choosing their glasses and the accessories, like the case and cleaning cloth. The glasses should be comfortable to wear, too. Soft nose pads and end pieces can help. The glasses need to be adjusted well by the optician.

It is important to explain to your child what the glasses are for. Role models might help, such as characters from books or celebrities from movies and TV who wear glasses. You can also put a pair of glasses on a younger child’s favorite stuffed animal.

Last but not least, rewards can also help, like a small gift if they manage to wear their glasses for a whole week.

Contact lenses correct the eye’s refractive power in a similar way to glasses. But they are worn on the tear film right in front of the cornea. Some people choose contact lenses because they have certain advantages over glasses. For instance, contact lenses are practically invisible to others, they usually don’t get in the way during sports, and they don’t fog up.

But it can be tricky to put contact lenses in at first. They may feel like a foreign object and irritate the eyes. In rare cases they can also cause infections. To prevent that, they need to be disinfected regularly with special cleaning products. It is also important to wash your hands well and dry them with a clean towel before putting the lenses in. Your ophthalmologist or optician will tell you how to use and take care of your contact lenses.

What’s more, you have to buy new contact lenses regularly. How often depends on the type you use.

Contact lenses are made from a special type of plastic. There are two main sorts of contact lenses, soft and hard, depending on the composition of the material. Soft contact lenses are usually comfortable to wear from the start. It takes a little longer to get used to hard contact lenses, but in the long term they are usually tolerated better, cause fewer infections, and don’t have to be replaced as often.

There are different types of contact lenses available depending on how long they can be used:

• Daily lenses are only worn for one day and are then replaced. They can’t be re-used, but that also means they don’t have to be cleaned. These are a particularly good idea for people who only wear contact lenses from time to time, like for sports.
• Weekly, monthly or annual contact lenses can be used for longer periods. But they have to be taken out before going to sleep to prevent infections. It’s important to disinfect them before putting them in again. There are special cleaning solutions for each type. Extended wear contact lenses that can also stay in your eyes at night are also available. Depending on the model, they only have to be taken out and disinfected every few days or every few weeks. That can be practical when traveling. But experts are critical of them because continuous overnight use can irritate the eyes and cause infections.

Bifocal or multifocal lenses are also available. They have different zones with various strengths. That means they can correct several errors at the same time. They may be a good solution for people who also have age-related farsightedness. How long the lenses can be worn depends on the material, model and manufacturer.

Children can wear contact lenses, too. There is no minimum age. Parents can best judge whether their child is capable of putting the lenses in and taking them out before going to bed by themselves, and regularly cleaning them. Parents can help with that if they need to. Daily lenses that don’t have to be disinfected are also an option for children at first, but it’s still important to make sure the contacts are removed at the end of the day.

It is also important to tell the child about any symptoms or warning signs that mean they shouldn’t wear them anymore, including itchy, stinging or reddened eyes, pain, and worse eyesight.

It is best to have glasses or contact lenses fitted by an optician. They are then adjusted to your individual vision, but also to things like the shape of your head and distance between your eyes. The most important information about your glasses or contact lenses, like the diopters or the model of the frames, can be noted in a special booklet.

In Germany, public health insurance covers the cost of the lenses for glasses that are prescribed by an eye doctor

• for children and teenagers no matter how severely farsighted they are, and
• for adults who have a farsightedness of at least +6.25 diopters in one or both eyes.

In these cases, the health insurance provider also covers the costs of new lenses if your vision has changed by at least 0.5 diopters since the last prescription.

Only the costs for standard lenses are covered. Extra charges for things like anti-reflection coating are normally not paid for. You also have to pay for the cost of the glasses frames yourself.

Public health insurers usually cover the costs of contact lenses for farsightedness of +8 diopters or more. Only the costs for hard contact lenses are typically covered. You can apply for the costs of soft contact lenses to be covered in exceptional cases, such as if you didn’t tolerate hard contact lenses. You have to pay for contact lens cleaning and care products yourself.

If you present a medical prescription at the optician’s, the health insurance contribution is deducted when you pay. But it’s possible that your insurer has agreements with certain opticians and only those opticians can deduct the costs. It is best to check with your health insurance provider before making a purchase.