Structural defect / astigmatism
When we talk about refractive errors – also known as astigmatism – we are usually referring to irregularities in the curvature of the cornea, and it is these irregularities that lead to visual disturbances. Since refractive errors generally refer to irregularities, it is therefore also an umbrella term for several different degrees of visual disturbances, and it occurs in conjunction with both long-sightedness and short-sightedness. In fact, most people have some degree of astigmatism from birth, but not all astigmatism affects vision to such an extent that glasses or other treatments are needed to correct the defect.
Why do people get structural defects?
Many people with refractive errors are born with them, and refractive errors are, as mentioned, very common. Refractive errors can be hereditary, and you may therefore be born with a refractive error for genetic reasons. Many people will also experience a decline in vision as they age, developing minor to more serious refractive errors. Changes in vision with age are quite common, and many people will experience problems with presbyopia, nearsightedness, or farsightedness later in life. With age, the lens of the eye naturally becomes increasingly cloudy, and many older people are therefore also affected by the well-known eye disease, cataracts. In addition, refractive errors can also occur in cases where the eye has been exposed to trauma or in connection with diseases of the eye.
Building defects with age
As we have briefly mentioned, it is quite common to experience changes in vision as we get older. This happens because the lens becomes increasingly stiff over time, reducing the ability to focus on objects close up. However, most people find that reading glasses solve the problem. It is also not uncommon for older people to experience a refractive error in one eye, while the other eye functions perfectly well. You can, of course, have glasses made with different strengths to take into account the vision in both eyes.
Nearsighted and farsighted
The two most common vision problems are commonly referred to as nearsightedness and farsightedness. A normal eye focuses images on the retina at the back of the eye (in the yellow spot), creating clear images of objects both near and far. In contrast, a nearsighted person looking at distant objects will find that the image is focused in front of the retina, making the image blurry. A farsighted person will often find that both near and distant objects are blurry because the lens of the eye focuses on a point behind the retina. Both nearsightedness and farsightedness can be diagnosed by your doctor or optician, after which the defect can be corrected with eyeglass lenses. Read more about treatments for refractive errors below.
Treatment of construction defects
The most common treatment for refractive errors that impair your vision is glasses and contact lenses. Glasses and contact lenses are a type of treatment that “corrects” irregular curvatures of the cornea to improve your vision quality. It is also possible to undergo surgical treatment, which usually involves laser treatment of the cornea to correct the irregularities. If you have an eye disease such as cataracts, there are special eye surgeries targeted at the individual eye disease.