Correcting Refractive Errors – All Information

Refractive errors – What exactly are they and what forms are there?

Emmetropia (from the Greek: in measure, fitting) means normal vision in ophthalmology. Another technical term is ametropia – it refers to an optically non-ideal eye, where incoming light rays are not correctly focused on the retina.

What does the term refractive error mean? A refractive error occurs when the shape or structure of the eye deviates from the norm. A refractive error can manifest in different ways. In most cases the eye’s ability to focus — its refractive power — is impaired, resulting in reduced visual acuity. This means that vision from one eye, either at distance or up close, can appear blurred. This is just one example.

The most common forms of refractive error are:

• Short-sightedness (myopia)
• Farsightedness (hyperopia)
• Corneal curvature (stabsichtigkeit, astigmatism)

The symptoms of refractive error vary depending on the type and from eye to eye. We can correct many of these refractive errors in our eye clinic in Stuttgart or Karlsruhe!

How do refractive errors develop?

Refractive errors occur when the cornea is misshapen or the eyeball is formed incorrectly. This affects the eye’s refractive power and causes light to fall on the retina incorrectly. The brain cannot form a correct image, and the result is a blurred perception.

As a result, objects in the distance or nearby objects appear blurred and are difficult to detect.

There are treatment methods to manage or eliminate the different types of refractive errors. The goal is to enable you to see sharply again. Glasses or contact lenses are always only a temporary solution for clear vision.

If you notice signs of ametropia or any eye condition in your eyes, it is advisable to consult an optician or ophthalmologist for an examination. Thanks to state-of-the-art procedures, refractive errors can now be corrected, and diseases that were previously untreatable or only partially treatable can often be healed.

What is corneal curvature (astigmatism)?

Unlike myopia and hyperopia, this is not about the length of the eyeball, although corneal curvature often occurs together with short- or long-sightedness. It is nonetheless a refractive error. Corneal curvature is also called stabsichtigkeit or astigmatism.

The cause is an uneven shape or surface of the cornea itself. Because the refractive power is altered, light beams cannot be correctly focused or refracted. Light rays do not form a single point on the retina. A corneal curvature (astigmatism) can be treated with SMILE® Pro or Femto-LASIK laser treatments.

We correct the refractive error known as astigmatism with laser methods up to 5 dpt. Above this level we implant a lens implant. If you decide to stop using glasses or contact lenses to see clearly, you should consider laser correction. With laser treatment, the cornea’s refractive power is precisely adjusted so that vision and visual acuity are optimised.

Higher-order refractive errors (aberrations)

In addition to the common refractive errors — myopia, hyperopia and astigmatism — there are so-called higher-order refractive errors. These can also impair vision in one eye or both eyes.

Despite correction with visual aids, the affected eye often does not achieve normal, full vision. There are also usually deficits in contrast sensitivity and night or low-light vision. With topography-guided LASIK we are able to correct these aberrations.