Vision problems

Myopia, hyperopia, astigmatism — clear vision at every distance

Refractive errors affect more than a third of the world's population. Is your distance vision blurry (myopia), your near vision blurry (hyperopia), or do objects look distorted (astigmatism)? These vision problems are not diseases as such, but natural variations in the shape of the eye — and today there is a wide range of effective ways to correct them.

At the practice, I offer a precise diagnosis and a correction plan tailored to your age, your profession and your lifestyle. For children, screening and myopia control are essential given the worldwide rise in myopia. For adults, solutions range from glasses and contact lenses to laser refractive surgery or lens implants.

Myopia Hyperopia Astigmatism Myopia control Refractive surgery
Anatomical diagram of myopia: an eye that is too long, with the image forming in front of the retina
Understanding

Ocular refraction — an optical balance

Refraction is the way your eye bends light to focus it on the retina. A small mismatch between the eye's optical power and its length creates a refractive error. Understanding how this works helps you make the best choices for correcting it.

Normal optics

The emmetropic eye

60 D of total power. Cornea 43 D + crystalline lens 19 D. Axial length ~23.5 mm. Result: a sharp image on the retina. Clear distance vision without effort.

Refractive errors

The three types

Myopia (eye too long), hyperopia (too short), astigmatism (irregular curvature). All can be corrected. Genetics + environment (screens, little time outdoors, eye rubbing).

Measuring refraction

Diopters (D)

The unit of optical power. −3 D (myopia), +2 D (hyperopia). The larger the number (in absolute value), the stronger the correction.

Key point

A natural variation

These conditions are not diseases, but variations in the shape of the eye. Heredity + environmental stress make them worse, especially in children. All of them can be corrected very well.

Comparative diagram — How light rays converge
Emmetropic NORMAL VISION SHARP image on the retina Myopic BLURRY AT DISTANCE Focus IN FRONT eye too long or too powerful Hyperopic BLURRY UP CLOSE Focus BEHIND eye too short or not powerful enough Astigmatic DISTORTED VISION Two DIFFERENT focal points non-spherical cornea Incoming ray Sharp focus (on the retina) Shifted focus (blurry image)
Focus: myopia

Myopia — blurry distance vision

Myopia affects 30–40% of Caucasians and more than 80% of people in East Asia. A worldwide epidemic, especially among children.

Definition

A myopic eye is either too long (axial length > 24 mm) or too powerful. Light from distant objects focuses in front of the retina, producing a blurry image on the retina. Result: your distance vision is blurry, but your near vision is often sharp.

Measurement: in negative diopters (for example, −3.00 D).

Degrees of myopia

  • Low myopia: −0.50 to −3.00 D
  • Moderate myopia: −3.00 to −6.00 D
  • High myopia: > −6.00 D

Risks of high myopia

Beyond −6.00 D, the risks increase:

  • Damage to the macula
  • Retinal tears and retinal detachment (more common)
  • Glaucoma (increased risk)
  • Early cataract (before age 60)
  • Damage to the choroid (myopic chorioretinopathy)

Myopia control in children

Screening and regular follow-up of myopic children are essential: several strategies can now significantly slow progression — see the dedicated section below.

A public health issue

A worldwide myopia epidemic

Myopia is increasing at an alarming rate. According to a landmark study published in Ophthalmology (Holden et al., 2016), half of the world's population will be myopic by 2050 — including nearly one in five of them with high myopia. This projection makes prevention and myopia control in children more essential than ever.

~30%
Of the world's population myopic in 2020
~50%
Worldwide projection for 2050 (Holden 2016)
~10%
High myopia expected in 2050 (≥ −6 D)
× 2
Prevalence doubled in Europe in 30 years

Why this explosion?

The factors are multiple and interact: genetic predisposition (two myopic parents = 6× higher risk for the child), prolonged near-vision activities (reading, screens, tablets), and lack of natural daylight due to less time spent outdoors. Studies from East Asia, where academic pressure is high and children spend long hours indoors in class, show the most extreme figures: more than 80% of young adults are myopic in some urban areas.

Why it is more than a mere inconvenience

Beyond dependence on glasses, high myopia (≥ −6 D) is associated with a significantly increased risk of serious eye disease in adulthood: retinal detachment, myopic choroidal degeneration, glaucoma, early cataract, macular neovascularization. Every diopter counts: slowing progression by 1 D in childhood substantially reduces the risk of complications at age 50. That is precisely the goal of myopia control.

Myopic children

Myopia control — slowing progression

1 in 3 children in Europe develops myopia before age 18. In the face of this epidemic, several strategies significantly slow its progression.

1/3
Of children myopic in Europe
2 h/day
Outdoors: recommended minimum
0.05%
Low-dose atropine (the most effective concentration in LAMP)
30–70%
Reduction in refractive progression depending on concentration (LAMP 2020)

Proven strategies

  • Daily atropine eye drops0.05% concentration as first-line treatment (LAMP study 2020), the most effective of the low concentrations tested
  • Orthokeratology (Ortho-K) — rigid lenses worn overnight that slow progression. A rare but serious risk of microbial keratitis requires strict hygiene
  • Peripheral defocus spectacle lenses and contact lenses — central correction combined with defocus in the peripheral retina
  • ≥ 2 hours outdoors per day — proven protective effect (ROC Trial, He 2015, JAMA)
  • Limit screen time — the 20-20-20 rule: every 20 minutes, look at something 6 meters (20 feet) away for 20 seconds

Recommended follow-up

  • Every year if myopia is confirmed (refraction + axial length)
  • Every 2 years if no myopia is detected
  • Routine screening in France: at 9 months (mandatory check-up), between 2 and 3 years, then between 5 and 6 years (before starting school)
  • Assessment of the rate of progression: how fast it progresses guides whether treatment should be intensified

Reference: Yam JC et al. Low-Concentration Atropine for Myopia Progression (LAMP) Study. Ophthalmology. 2020;127(7):910-919.

At the OPHTALIFE practice — how I approach myopia control

How I care for your myopic children

1 · Objective diagnosis

Axial length biometry at every visit

I routinely measure the eye's axial length (in mm) with a high-precision optical biometer. It is the true marker of myopia progression, far more reliable than refraction alone, which can fluctuate. An increase of more than 0.2 mm per year in a child should raise concern and prompt more intensive treatment.

2 · Medical treatment

Low-dose atropine prescribed at the practice

I prescribe 0.05% atropine as daily eye drops — the concentration found to be the most effective in the LAMP study. The schedule and duration are tailored to each child, with close initial follow-up and then yearly visits. Usually well tolerated at low concentrations; mild pupil dilation and temporary presbyopia (difficulty with near vision) may occur and are monitored.

3 · Optical solutions

Fitting at the practice

I personally fit overnight orthokeratology ("Ortho-K" lenses) at the practice: pre-fitting examination, choice of parameters, check-ups at day 1, day 7 and month 1, then every 3–6 months. For peripheral defocus spectacle lenses or contact lenses, I refer you to trained opticians. Care is thus coordinated and individualized.

The choice of strategy (atropine alone, atropine + defocus spectacle lenses, Ortho-K alone, or a combination) depends on age, rate of progression, lifestyle and family preferences. I always discuss the options with the parents before proposing a treatment plan.

Book a child myopia assessment ↗
Focus: hyperopia

Hyperopia — difficulty seeing up close

Definition

A hyperopic eye is too short or not powerful enough. Without correction, light rays would converge behind the retina — so the image reaching it is blurry. To compensate, the crystalline lens constantly changes shape to increase its power: this is accommodation. As long as accommodation works, the image becomes sharp again and hyperopia can go unnoticed, sometimes causing headaches.

Over time, the crystalline lens loses its ability to change shape. Symptoms then appear: blurry near vision first (where the accommodative effort is greatest), then distance eye strain at the end of the day as accommodation wears out.

Measurement: in positive diopters (for example, +2.50 D).

Symptoms

  • Blurry near vision
  • Eye strain, headaches (accommodative effort)
  • Accommodative strabismus in children (eyes turning in excessively)
  • Slightly blurred distance vision at the end of the day (accommodative fatigue)

Specific risks

High hyperopia carries a particular risk:

  • Shallow anterior chamber → closed iridocorneal angle
  • Acute angle-closure glaucoma — an eye emergency
  • YAG laser iridotomy often recommended as a preventive measure when the angle is narrow

Solutions

  • Glasses — simple correction
  • Contact lenses — improved peripheral vision
  • LASIK — up to about +5 D, depending on corneal thickness and keratometry; predictability decreases for high hyperopia
  • ICL and IPCL phakic lenses — internal refractive correction
  • Refractive lens exchange (PRELEX) — replacement with an intraocular lens (after age 50)
Anatomical diagram of hyperopia: an eye that is too short, with the image forming behind the retina
Focus: astigmatism

Astigmatism — distorted vision

Definition

Astigmatism is an asymmetry in the curvature of the cornea (most often), or sometimes of the crystalline lens. The cornea is not perfectly spherical like a soccer ball but shaped more like a football (rugby ball): two perpendicular meridians have different refractive powers, which creates two separate focal points instead of one.

Result: blurry or distorted images at all distances. Straight lines look slightly curved or doubled, and some orientations are blurrier than others.

Regular vs. irregular

  • Regular: the two meridians are at 90° to each other. Correctable with glasses (cylindrical lenses), toric contact lenses, laser or a toric lens implant.
  • Irregular: an uneven corneal distortion that cannot be corrected with glasses. It suggests keratoconus, a corneal scar, or the after-effects of corneal surgery. The diagnosis is confirmed by corneal topography.

Measurement

Astigmatism is written as a cylinder (in diopters, e.g. −1.75) and an axis (in degrees, from 0 to 180°). The higher the cylinder, the more marked the distortion.

Symptoms

  • Blurry or distorted vision at distance and up close
  • Distorted lines (walls, doors, signs)
  • Eye strain, headaches at the end of the day
  • Halos or double outlines around light sources (headlights, streetlights at night)
  • Squinting to see better

Solutions

  • Glasses with cylindrical lenses — a simple, effective solution
  • Toric contact lenses — better visual acuity, especially for moderate to high astigmatism
  • LASIK / SMILE — correct up to about 5 D of regular astigmatism
  • PRK / Trans-PRK — an option for thin corneas, for low astigmatism
  • Toric phakic lenses — when the cornea is not suitable for laser surgery
  • Toric intraocular lenses — during cataract surgery or refractive lens exchange
Anatomical diagram of astigmatism: irregular corneal curvature creating two separate focal points
Spherical cornea vs. toric cornea
Spherical Equal meridians ✓ Toric flat meridian steep meridian Unequal meridians → astigmatism
Highly myopic adults

High myopia in adults — lifelong monitoring

Beyond −6 diopters, myopia is no longer just a matter of correction: it is an at-risk condition that calls for regular specialist follow-up. Excessive elongation of the eye weakens the retina, the optic nerve and certain internal structures. Detecting complications early means preserving your vision for decades to come.

× 5 to 6
Risk of retinal detachment
× 2 to 3
Risk of chronic glaucoma
~10%
Myopic maculopathy in high myopia
−10 years
Earlier-onset cataract than average

My monitoring protocol at the practice

For every highly myopic patient (≥ −6 D), I offer a structured annual follow-up in addition to the refraction consultation:

  • Dilated fundus examination — examination of the entire peripheral retina to detect lattice degeneration, tears and holes that can precede a detachment.
  • Wide-field retinal photography (EIDON) — a digital image for year-to-year comparison.
  • Macular OCT — looking for choroidal neovascularization, myopic macular schisis, or epiretinal membrane.
  • Optic nerve OCT (RNFL) — interpreted with caution, as myopic optic discs are often atypical.
  • Visual field testing when indicated (suspected glaucoma).
  • Intraocular pressure measurement — high myopia is an independent risk factor for glaucoma.

Warning signs — seek care without delay

If you are highly myopic, certain symptoms require prompt consultation, ideally the same day:

  • Sudden onset of floaters (myodesopsia) or a sudden increase in their number
  • Flashes of light in your field of vision (photopsia)
  • A dark shadow or curtain appearing over part of your field of vision
  • Sudden loss of vision or distortion of straight lines (metamorphopsia)
  • A gray or dark central spot (scotoma) — suggests macular involvement

These signs may indicate an early retinal detachment, a macular hole or neovascularization — all eye emergencies in people with high myopia.

Book a high myopia assessment ↗ Learn more about glaucoma

Does this sound like you?

A consultation dedicated to assessing your refraction will help you understand exactly how you see and which solutions are best for you.

Book a refraction assessment ↗
Follow-up

When should I see my ophthalmologist?

Children — Pediatric follow-up

  • 9 months: mandatory health check-up including eye screening
  • 2 to 3 years: routine eye examination
  • 5 to 6 years: before starting school
  • Thereafter: every year if myopia is detected; every 2 years otherwise
  • Before refractive (laser) surgery: a stable refraction is required

Adults

  • Every 2 years: after age 30, even with no known problem (screening for eye diseases)
  • Before refractive surgery: a full assessment (cornea, crystalline lens, retina)
  • If your vision changes quickly or new symptoms appear
Beyond glasses

Surgical solutions

Laser or lens-based refractive surgery gives many patients freedom from glasses and contact lenses. To find out whether you are a good candidate, read my article "Am I eligible for refractive surgery?".

Corneal laser
LASIK
Corneal reshaping. Myopia up to −10 D, hyperopia up to +5 D, astigmatism up to 5 D.
Read →
Corneal laser
SMILE
Minimally invasive corneal lenticule extraction. Myopia up to −10 D, hyperopia up to +5 D, astigmatism up to −5 D. More comfortable after surgery.
Read →
Corneal laser
PRK / Trans-PRK
Surface refractive treatment, with no corneal flap. Ideal for thin corneas. Slower healing.
Read →
Presbyopia laser
PresbyLASIK
Creates corneal multifocality. For presbyopia alone, after age 45.
Read →
Internal lens
ICL & IPCL Phakic Lenses
A lens implanted in front of the crystalline lens. High myopia, high hyperopia, astigmatism.
Read →
Crystalline lens
Refractive lens exchange (PRELEX)
Replacement of the crystalline lens with an intraocular lens. Presbyopia, high myopia/hyperopia after age 50.
Read →
My scientific work

History and future of subtractive corneal surgery

I co-authored a recent review in the Journal Français d'Ophtalmologie tracing the evolution of corneal refractive surgery techniques (PRK, LASIK, SMILE) and their future prospects. The article reviews current indications, long-term results and future directions in refractive surgery.

Mechai N, Hage A, Baudouin C. Correction des erreurs réfractives par chirurgie cornéenne soustractive : histoire et perspectives. J Fr Ophtalmol. 2026;49(4):104829.

DOI ↗ All my publications ↗
Your care pathway

From consultation to clear vision

1
Comprehensive assessment
Refraction, topography, biometry, OCT. You understand exactly what your refractive error is and what your options are.
2
Choosing the technique
Glasses, contact lenses, laser or lens implant? We decide together based on your profile, your anatomy and your wishes.
3
Procedure (if surgery)
Outpatient, quick, under local anesthesia. Improved vision from the very next day.
4
Post-op follow-up
Visits at day 1, day 7 and month 1. Gradual stabilization. Adapting to your new vision: often 2–4 weeks.
Frequently asked questions

Answers to the most common questions

Next step

Do you have a question?

I will see you in consultation to assess your vision, understand how it affects your daily life, and discuss the best solution with you — glasses, contact lenses, or refractive surgery.

Cabinet OPHTALIFE — Boulogne-Billancourt (near Paris)
Former assistant surgeon, Hôpital des Quinze-Vingts (Paris)
Book online via Doctolib
Further reading

Related pages

Eye condition
Presbyopia
Near vision after age 45. How it differs from cataract, optical and surgical solutions.
Read →
Other condition
Keratoconus
Progressive irregular astigmatism. Diagnosis, prognosis and treatment (corneal cross-linking).
Read →
Surgery
LASIK
The benchmark laser refractive surgery. Myopia, hyperopia, astigmatism.
Read →
Bibliography

Scientific references

This page is based on international guidelines and landmark publications in ophthalmology. All sources can be verified via their DOI or PubMed.

  1. 1

    Holden BA, Fricke TR, Wilson DA, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-1042.

  2. 2

    Wolffsohn JS, Kollbaum PS, Berntsen DA, et al. IMI – Industry guidelines and ethical considerations for myopia control report. Invest Ophthalmol Vis Sci. 2019;60(3):M161-M183.

  3. 3

    Yam JC, Tang SM, Kam KW, et al. (LAMP Study Group). Low-Concentration Atropine for Myopia Progression (LAMP) Study: A Randomized, Double-Blinded, Placebo-Controlled Trial. Ophthalmology. 2020;127(7):910-919.

  4. 4

    He M, Xiang F, Zeng Y, et al. (ROC Trial). Effect of time spent outdoors on the development of myopia among children in China: a randomized clinical trial. JAMA. 2015;314(11):1142-1148.

  5. 5

    American Academy of Ophthalmology. Preferred Practice Pattern (PPP) — Refractive Errors & Refractive Surgery. aao.org

  6. 6

    Mechai N, Hage A, Baudouin C. Correction des erreurs réfractives par chirurgie cornéenne soustractive : histoire et perspectives. J Fr Ophtalmol. 2026;49(4):104829.

  7. 7

    Bullimore MA, Ritchey ER, Shah S, et al. The risks and benefits of myopia control. Ophthalmology. 2021;128(11):1561-1579.

  8. 8

    Donovan L, Sankaridurg P, Ho A, et al. Myopia progression rates in urban children wearing single-vision spectacles. Optom Vis Sci. 2012;89(1):27-32.

  9. 9

    Flitcroft DI. The complex interactions of retinal, optical and environmental factors in myopia aetiology. Prog Retin Eye Res. 2012;31(6):622-660.

The content of this website is for information purposes only and is not a substitute for a medical consultation. Any treatment decision should be made together with your ophthalmologist.