You wake up in the morning, enjoy the sunrise outside your window, shave, have a breakfast – the Upma looks delicious, dress and leave. At work, you go through reports, work on your computer, take phone calls, attend a meeting where the budget for the next year is projected, and return home at the end of a long day for your daughter to run up to you and settle in for some television before dinner and rest. Recollect how many of these tasks require you to ‘see’. The difficulty with a power cut to get about is indicative of how much we have taken our vision for granted.

There are a multitude of conditions from infections to effects of systemic diseases like diabetes that can affect what you see. However, uncorrected refractive error ranks as one of the leading public health challenges in eye care.

What is a Refractive Error?

Refractive error is a state in which optical system (the cornea and the lens) of the eye fails to adjust to bring parallel rays of light to focus on proper place (fovea on the retina).

There are various types of refractive errors –

• Astigmatism: Distorted vision resulting from an irregularly curved cornea, the clear covering of the eyeball.

• Hyperopia (far-sightedness): Difficulty in seeing nearby objects clearly.

• Myopia (near-sightedness): Difficulty in seeing distant objects clearly.

• Presbyopia: Universal difficulty in reading or seeing at arm’s length, due to age.

Is It Such A Big Problem?

In 2010, uncorrected refractive error was the leading cause of vision impairment and the second leading cause of blindness worldwide, affecting a total of 108 million people. The global burden of uncorrected refractive error is that the global economy loses $269 billion annually as a result of lost productivity due to uncorrected refractive error.

Studies have confirmed that the need for refractive error correction is higher for children. Results shown in the studies indicate that refractive error in children causes up to 77 percent of blindness and severe visual impairment (<6/60 in the better eye) in India.

Current data suggests that more than 90 percent of people with uncorrected refractive error, worldwide, reside in rural and low-income countries.

"Refractive errors, if uncorrected, result in an impaired or decreased quality of life for millions of people worldwide."

How Does It Affect The Person?

The most common complaint among adults with refractive errors would be the inability to see either for distance or near. Most others would complain of eye strain (asthenopia). This could manifest as heaviness, eye fatigue, blurred or double visio, and others. Refractive errors, if uncorrected, result in an impaired or decreased quality of life for millions of people worldwide.

Children are more vulnerable group, because uncorrected refractive error can result in to a dramatic impact on learning process and educational capacity. Not only do strong socio-economic factors such as poverty and the inability to access treatment influence the correction of a refractive error, but uncorrected refractive error can also contribute to the individuals and their families’ socio-economic status.

Can It Be Corrected?

A Refractive error can simply be diagnosed, measured, and corrected with the aid of optical corrective approach and devices such as spectacles and contact lenses or by refractive surgical procedures. It is diagnosed by making the person read a standard vision chart. After this, the power of the eye is estimated through a retinoscopy (a manual procedure where light is reflected into the eye) or using devices called Autor efractors. The corrected power lens is then placed in a trail frame and the spectacle correction is then estimated. Contact lenses could be an alternate to glasses. They not only help in better cosmesis, but could improve the optical clarity especially in higher powers and also improve the field of view.

Refractive LASER Surgery (LASIK) has become a popular procedure where the surface of the eye (Cornea) is reshaped to compensate for the power.

In certain persons where the anatomy of the eye does not permit this procedure, an ICL (Intraocular Collamer Lens) is floated into the eye.

Can This Be Prevented?

There is little evidence to prove any prevention of refractive errors. Diet does not seem to play a role. Alternative medicine and Yoga have not been evidenced to reverse any refractive errors.

Progressions of myopia in children could be slowed by adequate time spent outdoors in sunlight, avoiding the use of hand held devices, and in some with the use of specially formulated medications.

All children should be screened for refractive errors at the ages of one, three and five years. All adults above the age of 40 would need correction for presbyopia and should have an exam done. People with refractive errors could have other eye conditions and comprehensive eye exam including dilatation of the eye may be required periodically.

Invest in your eye health and enhance your productivity.