Refractive errors (ametropia) are the eye's optical defects: the image does not focus exactly on the retina. They affect the majority of the population and are corrected with glasses, contact lenses or, in some cases, surgery.
"Normal" (emmetropic) eye: light rays focus exactly on the retina.
Myopia
The eye is “too long”: vision is blurred at distance, sharp up close. Its frequency is rising sharply, particularly among the young. High myopia warrants regular monitoring of the retina.
The image forms in front of the retina: distance vision is blurred.
Hyperopia
The eye is “too short”: constant focusing effort can cause eye strain and headaches, with blurred near vision and later distance vision with age.
The image would form behind the retina: the eye must constantly accommodate.
Astigmatism
A curvature defect of the cornea: imprecise or distorted vision at all distances, often associated with myopia or hyperopia.
The cornea is not perfectly spherical: two distinct focal planes, the image is distorted.
Presbyopia
The natural loss of near focusing after 40-45: needing to hold text further away to read is the classic sign. It affects everyone and progresses until about age 60.
Frequently asked questions
Can surgery correct these defects?
Yes, in some cases. In older patients, cataract surgery is also an opportunity to correct myopia, hyperopia, astigmatism and presbyopia through the choice of implant (monofocal, EDOF, multifocal).
Book an appointment
Consultations in Boulogne-Billancourt (Ophtalife) and Saint-Maur-des-Fossés (Beaurepaire).