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What is refractive error?

Refractive errors are eye disorders caused by irregularity in the shape of the eye. This makes it difficult for the eyes to focus images clearly, and vision can become blurred and impaired.

Refractive errors include eye problems such as myopia (short-sightedness), hyperopia (long-sightedness) and astigmatism (caused by an irregularly curved cornea).

They also include presbyopia, a normal ageing change, where the eye is no longer able to focus at close range.

These eye disorders can be particularly problematic in developing countries, where those affected may not be able to afford sight tests or spectacles to help improve their vision. For a child, something as simple as a pair of glasses can mean the difference between a bright future and being trapped in a cycle of poverty.

What’s more, those living in remote communities may not have access to eye care – in sub-Saharan Africa, for example, two-thirds of ophthalmologists and optometrists are based in capital cities, leaving a shortage of trained eye care professionals working in rural areas.

Arthur rubs his left eye with his left hand

“When I didn’t have glasses, I did not see clearly. Things were not well with me.”

Read Arthur’s story

Refractive errors are the world’s leading cause of visual impairment

161 million people worldwide have uncorrected refractive errors

Source: The Lancet Global Health Commission

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How is refractive error treated?

A young boy sits in a chair while a man in a suit examines his eyes using optometry equipment.

Eye test

The patient is given an eye test to find out how their vision is affected.

A child has his eyes examined with trial lenses.

Diagnosis

During the test, they’re asked to read letters or symbols on a chart.

A boy wearing glasses smiling.

Correction

If they have refractive error, it can then be corrected with spectacles.

Find out how we test people’s vision for refractive errors

What we’re doing

Since 2004, Sightsavers has dispensed nearly eight million pairs of spectacles across Africa, Asia and the Caribbean as part of our work in universal health care.

We have also helped to train 745 optometrists and 437 optometric technicians, who are able to carry out sight tests, diagnose eye problems and help to treat people with low vision in some of the poorest parts of the world, who may otherwise not have access to eye healthcare.

Sightsavers’ School Health Integrated Programming (SHIP) project, which started in 2016, has screened schoolchildren in Cambodia, Ethiopia, Ghana, Senegal, Liberia and Pakistan for health problems such as poor vision.

As part of the SHIP project, teachers have been trained to carry out basic eye tests and refer children for further treatment. More than 200,000 children have been screened for eye problems, and thousands of students have been given spectacles.

Read Sightsavers’ refractive error strategy to find out more about our work to treat refractive error.

A school student has her eyes tested while wearing optical glasses: an eye health worker's hand is changing the lenses in the glasses.

Improving health and vision in schools

The Sightsavers-supported School Health Integrated Programming project (SHIP) screens schoolchildren for health problems and provides spectacles and treatment where needed.

Read about the project

Page last reviewed: October 2024
Next review due: October 2027
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