Astigmatism refers to a condition wherein the shape of the eye is not perfectly round.
In a normal eye, the front surface called cornea or the layer beneath called the lens, are usually shaped like a perfect round ball. However, an individual with astigmatism has an oval-shaped eye. Therefore, objects further away appear very hazy and blurry and affect the visual ability of the person in their day to day activities.
In other words, astigmatism is a refractive error, where the light rays entering the eye from a distant artifact, are bent in an unconventional way and hence cannot be focused to form a clear image on the retina.
The primary cause of this eye defect is still unknown, although a severe injury to the eye or a complicated surgical procedure in the region nearby the eyes could lead to the person developing astigmatism. In a majority of cases reported, however, the onset of astigmatism is from birth itself.
As childhood is the most common phase in which this ailment advances, regular screening of both the eyes, to detect any flaws, is a must for children in all their initiative years - newborn to kindergarten right up to primary school.
The characteristic signs and symptoms that an individual with astigmatism experiences include:
- Inaccurate vision, particularly of objects further away like in the case of myopia
- Pain and strain in the eyes
- Distorted vision at night-time
Diagnosis And Treatment
The ophthalmologist performs a complete eye exam, once the patient reports difficulty in seeing far-off things. This comprises a sequence of tests to detect how your eyes refract light onto the retina. The doctor will shine a bright light directly onto your eyes to detect if pupil dilation is normal. He or she will also request you to view and read materials with your naked eye, as well as with the assistance of lenses.
Once the test results are thoroughly examined, the healthcare provider will prescribe the exact corrective power lenses, either in the form of eyeglasses or contact lenses, as per your age and convenience. The power is indicated prefixed with a “C” for cylindrical lenses followed by a positive or negative value to denote the level of correction required to provide accurate focus.
In very severe curvature defects in the eye, merely prescribing rectifying lenses will not suffice to enable visual precision. The physician then decides to perform an amendment process, which is laser surgery to restructure the arcs of the cornea, by a method known as LASIK (Laser-Assisted in-Situ Keratomileusis).