Factors that affect Astigmatism
Astigmatism often combined with shortsightedness or longsightedness, occurs when the clear cornea surface is not uniformly smooth. It has depressions and
elevations as in surface of the moon. Because of that, the eye lacks a single point of focus. People with astigmatism may have a random, inconsistent vision
pattern, wherein some objects appear clear and others blurry. Astigmatism is usually present from birth but is typically not recognized until later in life.
Most astigmatism is fully correctable. It neither improves nor worsens over time.
Causes of Astigmatism
Astigmatism can be hereditary and is often present at birth. It can also result from pressure from the eyelids on the cornea, incorrect posture or an
increased use of the eyes for close work.
Clinical Presentation
People with astigmatism often complain of on and off headaches, fatigue, eyestrain, blurred vision or tilting of the head to achieve better focus. While
these symptoms may not necessarily be the result of astigmatism, one should go for a routine eye examination as soon as possible.
Toric Lens correction for Astigmatism
In Astigmatism, rays of light in one plane or axis focus on the retina, whereas rays that enter at right angles either converge or diverge producing a
scattered and blurred image. Toric lens of suitable power is placed before the eye so as to neutralize the meridian irregularity and bring the image to point
focus. This toric lens may be incorporated into shortsight or longsight correction and can be used as spectacles or contact lens.
Laser Surgery for Astigmatism
Laser eye surgery can correct astigmatism, by changing the shape of the cornea. While there is more than one type of refractive surgery, LASIK and LASEK
are the present trend in refractive Laser surgery.
The parameters for achieving good vision after Laser surgery are corneal thickness, good retinal health and best corrected vision with the present glass.
The above mentioned factors will individualize the outcome of the Laser surgery.