Astigmatism - The Cause of Blurry Vision - Causes, Risks & Cure
A very common vision condition, Astigmatism, is an optical defect that results in blurred vision due to formation of multiple focus points either due to asymmetrical curvature of the eye lens or irregular shape of cornea. It is also known as eye refractive error.
People with astigmatism are unable to view far or near objects clearly. A slight degree of astigmatism often exists in people, but usually does not cause severe vision problems; hence, no treatment is required. However, a greater degree of astigmatism may result in various complications such as blurred vision and amblyopia. Some symptoms of severe astigmatism include:
- Blurred or distorted vision
- Migraine headaches (View ocular migraine)
- Weariness and fatigue
- Eye strain
- Eye squinting
This is how a person with different forms of astigmatism sees text.
Astigmatism is classified as follows:
1. Myopic astigmatism: Refractive error of nearsightedness
2. Hyperopic astigmatism: Refractive error of farsightedness
3. Mixed astigmatism: Refractive error of both farsightedness and nearsightedness
4. Regular astigmatism: Refractive error due to the all over equality in cornea shape
5. Irregular astigmatism: Refractive error due to irregularity in cornea shape
How common is Astigmatism?
Results of recent studies on astigmatism reveal:
- American study shows 28% astigmatism signs, found in 3 out of 10 children, ranging from 5 to 17 years.
- Bangladesh study shows 32.4% astigmatism signs, found about in 1out of 3 adults, ranging from 30 years to above.
What Causes Astigmatism?
Although astigmatism can occur due to several different reasons, not all of them have been confirmed. Some major causes may be:
- Eye surgery, injury or any eye infection
- A lump inside an eye
- Eye condition of keratoconus relating to thinning and stretching of cornea.
- Inherited defect
- Wrong posture, excessive strain or pressure on eyes
- Eye refractive error of nearsightedness or farsightedness
Astigmatism can often be corrected and there are a few options to do so:
- Using process of orthokeratology recommended by an eye specialist
- Wearing eye glasses or standard soft, hard or rigid contacts
- The following surgeries are being performed for correcting astigmatism:
1. Laser refractive surgery involves the correction and normalization of the curvature of the cornea
2. Radial keratotomy surgery involves the flattening and reshaping of the cornea
3. Corneal transplantation surgery, involving replacement of defective cornea with a donor one
4. Toric intraocular lens implantation surgery, involving replacement of your natural eye lens with a toric lens (an artificial lens)
A routine eye checkup by your optometrist confirms if astigmatism is present. This examination involves one of the following vision tests:
• A test is performed using the keratometry technique for measuring the corneal curvature of your eyes.
• In some situations, corneal topography is performed for a more detailed view.
• Using the refraction process, an eye specialist can measure the degree of a patient's astigmatism severity.
• A visual acuity test is performed for measuring the eyes' focal strength.
•A test, known as retinoscopy, may be also performed for astigmatism diagnosis.
When to Consult a Medical Professional
It's imperative for you to have regular eye checkups to detect any vision problems before they become more troublesome. You should contact your eye specialist as soon if you notice any of the symptoms discussed above.