Refractive errors (myopia, hyperopia and astigmatism) and presbyopia occur when the eye cannot focus light precisely onto the retina, leaving vision blurred. They are not eye diseases — simply a mismatch between the eye’s length and the focusing power of its cornea and lens. Glasses and contact lenses correct the blur, while laser eye surgery, implantable contact lenses (ICL) and refractive lens exchange from £4,300 per eye can correct it permanently.
What are refractive error and presbyopia?
For clear vision, light entering the eye must be focused to a sharp point on the retina. A refractive error means the focus falls in front of or behind the retina, usually because the eyeball is slightly too long or too short, or the cornea is unevenly curved. The three common types are myopia (short-sightedness — distance is blurred), hyperopia (long-sightedness — near work is blurred and tiring) and astigmatism (an oval cornea that blurs vision at all distances).
Presbyopia is different. From around the age of 40 the eye’s natural crystalline lens gradually stiffens and loses its ability to change shape, so focusing on close objects — a phone, a menu, small print — becomes harder. It is a normal part of ageing that affects nearly everyone, which is why reading glasses become so common in mid-life.
Symptoms
The symptoms depend on the type of error, but commonly include:
- Blurred distance vision — road signs or the TV look fuzzy (myopia)
- Blurred or tiring near vision — reading is uncomfortable (hyperopia and presbyopia)
- Holding things at arm’s length to read small print (presbyopia)
- Eye strain, headaches or squinting, especially after screen work
- Distorted or doubled vision at all distances (astigmatism)
- Difficulty seeing at night or with glare
Tired of glasses and contact lenses? A vision-correction consultation tells you exactly which procedure suits your eyes, prescription and lifestyle.
Book a vision-correction assessmentCauses & risk factors
Refractive error and presbyopia come down to the optics and ageing of the eye rather than illness. Contributing factors include:
- Eyeball length — a longer eye causes myopia, a shorter eye causes hyperopia
- Corneal shape — an unevenly curved cornea causes astigmatism
- Age — lens stiffening after 40 causes presbyopia in almost everyone
- Family history — refractive errors, especially myopia, run in families
- Prolonged close work and limited time outdoors in childhood, linked to rising myopia
How it is diagnosed
Diagnosis is quick, painless and precise. A refractive and surgical-planning assessment includes:
- Visual acuity test — reading a letter chart to measure how clearly you see.
- Refraction — fine-tuning lenses to find your exact prescription for distance and near.
- Autorefraction & topography — scans that map the cornea’s curvature.
- Biometry — precise measurements of the eye used to plan laser or lens surgery and select lens power.
- Ocular health check — to confirm the eyes are healthy and suitable for treatment.
Treatment options
Glasses and contact lenses correct the blur day to day, but several procedures can correct vision permanently. The right one depends on your age, prescription and whether presbyopia is present — your consultant will recommend the best fit.
- Laser eye surgery — reshapes the cornea to correct myopia, hyperopia and astigmatism. See our laser eye surgery overview, including PRESBYOND blended vision for presbyopia.
- Implantable contact lens (ICL) — a permanent lens placed inside the eye, ideal for high prescriptions or thin corneas. See ICL surgery.
- Refractive lens exchange (RLE) — replaces the eye’s natural lens with a premium multifocal or extended-depth lens, correcting both refractive error and presbyopia at once. See RLE and RLE pricing.