Astigmatism is a common vision condition that leads to blurred vision. It results when the cornea (the clear front cover of the eye) is irregularly shaped or at times due to the curvature of the lens inside the eye. Light fails to focus properly on the retina (the light-sensitive surface at the back of the eye) due to an irregularly shaped cornea. This results in blurred vision, irrespective of the distance at which the viewer is. This can also result in the eye discomfort and headaches.
Majority of people show at least some degree of astigmatism. Slight astigmatism generally does not affect the vision or require treatment.
Astigmatism is often known to simultaneously occur with other vision conditions like myopia (nearsightedness) and hyperopia (farsightedness). These vision conditions together are referred to as refractive errors as they show their effect on the bending or refraction of light.
No specific causal relationship has been found for astigmatism. It is known to be hereditary and is normally found from the time of birth. It can show variation with increased or decreased intensity over time.
Testing for astigmatism is part of the comprehensive optometric examination. If required, optometrist can correct astigmatism by altering the way light enters the eyes with the help of eyeglasses or contact lenses.
A corneal procedure called orthokeratology (ortho-k) is another option available for treating astigmatism which is a noninvasive, painless procedure that requires the patient to wear a series of specially designed rigid contact lenses to help slowly recover the shape of corneal curvature.
Laser surgery can help treat some types of astigmatism. It does so by changing the shape of the cornea by removing a small portion of eye tissue.
Astigmatism is an imperfection in the curvature of cornea (the clear, round dome covering the eye’s iris and pupil) or in the shape of the lens. Normally, the cornea and lens are smooth and curved equally in all directions, helping to focus light rays sharply onto the retina at the back of eye. However, if cornea or lens is not smooth and evenly curved, light rays aren’t refracted properly resulting in what is called a refractive error.
Corneal astigmatism is due to an irregularly shaped cornea, whereas, lenticular astigmatism results from the distorted shape of the lens. As a result of either type of astigmatism, vision for both near and far objects appears blurred or distorted.
Astigmatism in some cases is present right from the time of birth — in fact, most people probably are born with some degree of astigmatism — together with other refractive errors: nearsightedness (myopia) or farsightedness (hyperopia).
There are two types of astigmatism – regular and irregular. In regular astigmatism, cornea is curved more in one direction than the other. It’s more common than irregular astigmatism and can be corrected with glasses or contact lenses.
In irregular astigmatism, the corneal curvature is uneven across the surface of the eye. Instead of being curved mostly in one direction, it could be curved in multiple directions, or the curve could be steeper towards the bottom.
Irregular astigmatism is many a times is caused due to an eye injury that leaves a scar on the cornea. It can be corrected with contact lenses but not with the glasses.
A relatively rare condition called keratoconus that involves the cornea becoming progressively thinner and cone-shaped is also one of the causes of astigmatism. It leads to a large amount of astigmatism, which causes poor vision that cannot be clearly corrected with eyeglasses. People with keratoconus usually need contact lenses for clear vision and eventually may need a corneal transplant.
Astigmatism can affect both children and adults. Some patients with slight astigmatism may not experience much change in their vision. It is important to regularly undergo eye examinations so as to detect any astigmatism early on in children.
Signs and symptoms include:
- Distorted or blurred vision at all distances
- Difficulty driving at night
It is important to be aware of any changes in the vision in order to detect any common vision problems and get early treatment.
It is possible to be unaware of mild astigmatism. This is especially true for children, who are not aware of their vision being other than normal. Some adults may also have mild astigmatism without any symptoms.
Astigmatism treatment in India involves use of eyeglasses, contact lenses, or surgery. Individual lifestyles also affect the way astigmatism is treated.
Eyeglasses are the simplest and safest way to correct astigmatism.
Contact Lenses cause a more precise refraction or focus by becoming the first refractive surface for light rays entering the eye. Contact lenses do help provide clearer vision, a wider field of vision, and greater comfort in many cases. They are a safe and effective option. However, contact lenses are not right for everyone. Discuss this with your eye care professional.
Refractive Surgery aims to change the shape of the cornea permanently. This helps restore the focusing power of the eye by allowing the light rays to focus precisely on the retina for improved vision. There are many types of refractive surgeries. An eye care professional can help decide if surgery is a right option or not.
Astigmatism treatment at Sanjeevan focuses on the correction of the curvature of the affected cornea or the lens. This is meant to help the patient suffering from astigmatism to focus better which would result into a sharper image.
In rare cases of irregular astigmatism with our treatment, we induce more oxygenation in the cornea and the lens and improve the flexibility of the lens which ultimately results into improvement of vision.