Refractive error

Refractive error, also known as refraction error, is an issue with precisely focusing light on the retina caused by the shape of the eye or cornea. Near-sightedness, far-sightedness, astigmatism, and presbyopia are the most frequent kinds of refractive error.

Near-sightedness blurs distant items, far-sightedness and presbyopia blur close objects, and astigmatism causes objects to look stretched out or hazy. Other signs and symptoms include double vision, headaches, and eye strain.

Near-sightedness is caused by the eyeball being too long, far-sightedness by the eyeball being too short, astigmatism by the cornea being the incorrect shape, and presbyopia by the lens of the eye ageing to the point that it can no longer change form properly.

Some refractive errors are more common in those whose parents are afflicted. The diagnosis is made by an eye examination.