is an eye disorder that affects the curvature of the eye. This means that the
shape of one's eyes or the eye lens is irregular and this prevents light from
being focused on to the retina properly. It is usually characterized by blurred
Astigmatism occurs to most people today, but only to different extents. It can happen to a mild extent, which is not a cause for concern, but it can also have a negative effect on eye sight, blurring vision at times.
Astigmatism is a very common eye disorder, and it usually occurs along with other common eye disorders like Myopia (short-sightedness) and Hyperopia (far-sightedness). Together, these eye disorders are medically referred to as refractive errors.
Causes of Astigmatism
Medical research has shown that astigmatism can occur even at birth, or after an eye injury, disease or surgery. It has also been identified to be hereditary.
The causes can be known based on the type of Astigmatism one has.
The two types of Astigmatism are:-
Corneal Astigmatism: This kind of astigmatism occurs when the cornea is curved improperly or imperfectly. Thus, in this case, the cornea has a distorted shape that prevents light rays from being refracted properly. Other cornea-related disorders like Keratoconus - wherein the cornea thins and degenerates gradually to become more conical in shape.
Lenticular Astigmatism: The other form of astigmatism deals with an imperfect or an improper eye lens. With the lens being curved imperfectly, the image that reaches the retina is imperfect, thus causing blurred vision. Some times lenticular astigmatism is seen in patients with diabetes. Fortunately, treatment of diabetes can also lead to reduction in astigmatism.
Symptoms of Astigmatism - Do you have Astigmatism?
Although diagnosis of the condition of Astigmatism is done through various eye check-ups and eye tests, astigmatism usually occurs with the onset of headaches, excessive squinting, fatigue, blurry vision, eyestrain, distorted vision and photophobia (sensitivity to light).
Diagnosis can be made with the help of visual acuity tests, regular eye tests, use of a Snellen Chart, Keratometer, a Keratoscope, or an astigmatic dial.
Treatment for Astigmatism
Astigmatism can be corrected with the prescription of corrective lenses (eye glasses or contact lenses) or refractive surgery.
Eyeglasses are the primary means to correct blurred vision brought upon by astigmatism. Cylindrical lenses are generally prescribed with a single lens to provide clarity of objects at all distances.
Contact Lenses and their effects: - While contact lenses are also prescribed by eye doctors and opticians alike, it is important to know the pros and cons of using contact lenses to cure astigmatism.
Regular cleaning and maintenance is required for contact lenses. The delicate nature of the lenses means that mishandling can lead to other eye disorders as well. However, it is still recommended as the best way to improve vision and correct astigmatism.
Astigmatism and Lasik/Laser Surgery: -
Photorefractive Keratectomy (PRK) is one of the laser surgery techniques used to treat astigmatism. Here, the protective layer or tissue of the cornea is removed and another laser changes the shape of the cornea. However, this laser treatment is known to be painful.
Laser in situ keratectomy (LASIK) is a recent development in the field of eye treatment technology. It has been favoured largely because it is known to cause the least amount of pain when compared to other corrective laser surgeries. It involves using a laser to make a thin cut into the cornea and then shaping the cornea with the help of an excimer laser.
Other measures include Orthokeratology and LASEK (Laser epithelial keratomileusis)