General Eye Conditions and Tests
What is a refractive error?
A refractive error means the eye does not focus light exactly on the retina, so the image is blurred. Short sightedness blurs distance, long sightedness makes sustained near work tiring and can blur both distances, and astigmatism blurs detail at all distances because the cornea is more curved in one direction. Glasses or contact lenses correct all three.
The three main types
- Myopia, or short sightedness, where the eye is slightly too long and distant objects blur
- Hypermetropia, or long sightedness, where the eye is slightly too short, so the focusing muscle works constantly and near work tires the eyes
- Astigmatism, where the cornea is shaped more like a rugby ball than a football, so detail is blurred or doubled at every distance
Understanding your prescription
The first number describes short or long sightedness, a minus figure meaning short sighted and a plus figure long sighted. The next two describe astigmatism and its orientation. An addition figure gives extra power for reading. Higher numbers mean a stronger prescription, not necessarily an unhealthy eye, although high prescriptions carry a greater risk of other eye conditions.
Correction options
- Spectacles, the simplest and safest correction
- Soft or rigid contact lenses, fitted and reviewed, with careful hygiene to avoid corneal infection
- In children, glasses plus treatment of any associated lazy eye or squint
- Myopia control for children whose short sightedness is increasing
Why regular review matters
Prescriptions change, particularly during childhood growth and again from the forties. A rapid change in an adult can indicate diabetes or a developing cataract, so it is assessed rather than simply corrected with new lenses. Standard Eye Specialist Hospital provides refraction and dispensing of prescription glasses alongside full eye examination.
Frequently asked questions
- Can a refractive error be cured?
- It can be corrected with glasses or lenses. Some adults are suitable for refractive surgery, which is a separate discussion requiring detailed assessment of the cornea.
- Does wearing glasses weaken the eyes?
- No. Glasses simply focus light correctly. Eyes change because of growth and age, not because of glasses.
Concerned about these symptoms?
Arrange an eye examination with our consultant ophthalmologist in Garki, Abuja.
Related answers
- Why do I need reading glasses after forty?
- Why is my vision blurred?
- What happens at a comprehensive eye examination?
Return to all general eye conditions and tests answers.