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. What’s more, those living in rural areas 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.
The patient is given an eye test to find out how badly their vision is affected.
During the test, they're asked to read letters or symbols from a chart.
If they have refractive error, it can then be corrected with spectacles.
We have also helped to train 732 optometrists and 433 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 ran throughout 2016, screened schoolchildren in Cambodia, Ethiopia, Ghana and Senegal for health problems such as poor vision.
As part of the project, teachers were trained to carry out basic eye tests and refer children for further treatment. During the project, 57,400 children were screened for eye problems and 1,000 were given spectacles.
Download Sightsavers refractive error strategy (pdf) to read more about our work to treat refractive error.
For children such as Riya, something as simple as a pair of glasses can mean the difference between a bright future and being trapped in a cycle of poverty.
Read her storyTo mark World Sight Day 2019 on 10 October, Sightsavers country offices celebrated by highlighting the need to provide good-quality eye care to everyone.
By using economics, we can make sure our school eye screening programmes are affordable and efficient, ensuring thousands of children in poorer countries can get the eye care they need.
The latest from Kenya, where Sightsavers staff have been carrying out eye screenings in a refugee camp in Turkana. Plus news from India and Nigeria.