Astigmatism – this is a fairly common pathology of the refraction of the eye, associated with an irregular shape of the cornea or lens. The literal translation of the name of this disease from Greek means “inability of the eye to connect the rays to one point, that fall on him” (from the Greek word “stigmas” – point). As a result, a person sees the surrounding objects as distorted, blurred, and straight lines – bent.
The cornea and lens of a normal, healthy eye have a smooth spherical surface. With astigmatism, their sphericity is disturbed, it has different curvature in different directions: denser in one direction and convex in another. So, that light rays, which pass through a deformed cornea or lens are focused on the retina at more than one point, and several at once. Therefore, the image is perceived by the eye indistinctly. Usually, astigmatism is combined with myopia (myopic astigmatism), or with farsightedness (hypermetropic astigmatism).
What types of astigmatism are there??
Like any disease, astigmatism of a weak degree can exist even in a normally functioning eye. But strong degrees of astigmatism seriously affect vision and are eliminated with the help of appropriate glasses.
Astigmatism is farsighted, short-sighted and mixed: along one axis farsighted, on another – short sighted. At the same time, part of the light flux is concentrated to the retina of the eye, and part – behind her.
Who is prone to astigmatism?
How is astigmatism diagnosed??
In most cases, a person simply does not notice astigmatism of a weak degree. Seeing everything in a slightly blurred form is the norm for her and, she may not know about it, that in reality the image should be sharper. Most often, astigmatism manifests itself in the form of headaches, which occur when there is an increased load on the eyes while working at the computer or when reading. If you have a feeling after visual strain, double vision, then there is a high probability, that you suffer from astigmatism.
How to get rid of astigmatism?
Glasses and contact lenses do not treat astigmatism, they only correct vision.
You can completely get rid of astigmatism only with the help of surgical intervention.
There are several types of operations with different methods to eliminate astigmatism:
- Thermokeratocoagulation – is performed to correct far-sighted astigmatism. This is thermal cauterization of the peripheral zone of the cornea with a heated metal needle. When burning, the curvature of the cornea increases, which means, its refractive power increases.
- Radial keratotomy – used for myopia or mixed astigmatism. This is the application of radial notches on the cornea to weaken the refraction along the enhanced axis.
But these methods already belong to the history of ophthalmic surgery. She came to replace them laser correction, which makes it possible to more accurately calculate the final result.
2 thoughts on “Astigmatism”
What are the main symptoms and causes of astigmatism, and how can it be effectively diagnosed and treated?
Regards, PTS Terbaik
Main Symptoms of Astigmatism:
Blurred or distorted vision at all distances
Eye strain or discomfort
Headaches, especially after visual tasks
Difficulty seeing clearly at night
Squinting to improve focus
Diplopia (seeing multiple images)
Eye discomfort or fatigue
Causes of Astigmatism:
Irregular Corneal Shape: The most common cause; the cornea has an uneven, oval shape rather than a symmetrical spherical shape.
Lens Shape: Less commonly, the lens inside the eye may be irregularly shaped.
Genetics: Often hereditary; tends to run in families.
Eye Injury or Surgery: Can alter corneal shape.
Certain Eye Diseases: Conditions like keratoconus (progressive thinning of the cornea) can cause or worsen astigmatism.
How to diagnose Astigmatism:
Comprehensive Eye Exam: Conducted by an optometrist or ophthalmologist.
Refraction Tests: Using a phoropter to determine the correct lens prescription.
Keratometry: Measures the curvature of the cornea.
Corneal Topography: Maps the surface curvature of the cornea in detail.
Visual acuity tests: To assess the clarity of vision at various distances.
Treatment Options for Astigmatism:
Correction of astigmatism:
Eyeglasses: Special cylindrical lenses to compensate for irregular curvature.
Contact Lenses: Toric lenses are designed specifically for astigmatism.
Refractive Surgery:
LASIK or PRK: Laser procedures that reshape the cornea to correct irregularities.
Orthokeratology: Specially designed rigid contact lenses worn overnight to temporarily reshape the cornea.
Management of Underlying Conditions: Treating associated eye conditions if present.