If you’ve ever struggled to see clearly—whether at a distance, up close, or both—it may be due to a refractive error. The most common types include nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. These conditions occur when the eye cannot focus light properly onto the retina, often due to the shape of the eye or cornea. The result is blurred or distorted vision that can affect everyday activities like reading, driving, or using a screen.
Refractive errors are not classified as diseases but rather as natural anatomical variations of the eye. However, when left uncorrected, they are the leading cause of moderate to severe visual impairment worldwide, contributing significantly to lost productivity and reduced quality of life (Nature, 2024). You may have one or a combination of these errors without realising it.
In this guide, we explain the causes and symptoms of each refractive error, how they affect your daily life, and the range of treatment options available—from glasses and contact lenses to modern laser vision correction and lens-based procedures.
How Your Old Frames Can Change a Life
At Sandton Eye Clinic, we recognise that clear vision is a gift not everyone can access. Uncorrected refractive errors remain the leading cause of visual impairment worldwide —affecting over 157 million people and contributing significantly to disability-adjusted life years (DALYs). Many individuals in underserved communities simply cannot afford prescription glasses, even though a simple pair of spectacles could dramatically improve their quality of life. Whether you’re exploring laser vision correction to reduce your dependence on glasses, or you’re content with your current eyewear, we invite you to donate your preloved frames to our ongoing partnership with Lions BrightSight. Your contribution may help restore sight and independence to someone who shares the same visual challenges you once faced.
We are a proud donation drop-off point for Lions BrightSight. If you’d like to donate your pre-loved spectacles, you’re welcome to give them in at our reception.
Nearsightedness (Myopia)
Myopia is when distant objects appear blurry, while close-up objects are clear. This happens when the eyeball is too long or the cornea is too curved.
Common symptoms:
- Difficulty seeing road signs or presentations
- Squinting to see far-away objects
Four practical tips for living with myopia:
- Outdoor Time Can Help Slow Progression
Spending more time outdoors—especially during childhood—has been shown to slow the progression of myopia. Natural light and long-distance focusing help reduce eye strain, which is why eye specialists often recommend at least 90 minutes of outdoor activity per day for children at risk of developing myopia. - Your Glasses Prescription May Not Be the Same for All Tasks
If you have myopia, you might benefit from different prescriptions for different activities. For example, a slightly reduced prescription for computer use or reading may help reduce eye strain, while your full prescription ensures clear distance vision for driving or watching TV. Always consult your optometrist or ophthalmologist before making changes. - Night Driving Can Be More Challenging
People with myopia often notice increased difficulty seeing clearly at night, a condition known as night myopia. This is due to the pupil dilating in low light, which can accentuate refractive errors. If night vision is affecting your confidence behind the wheel, consider speaking to your eye care professional about glasses specifically for night driving or evaluating your suitability for vision correction procedures. - Consider Your Vision Correction Options
If you’re tired of relying on glasses or contact lenses for distance vision, procedures like LASIK, PRK, or Implantable Contact Lenses (ICL) may offer a long-term solution. A consultation with a refractive surgeon can determine the safest and most effective option for your eyes and lifestyle.
Farsightedness (Hyperopia)
Hyperopia is when close objects appear blurry, but distant vision is clear. It’s caused by a shorter eyeball or a flatter cornea.
Common symptoms:
- Eye strain or headaches when reading
- Blurry vision when working on a computer
Four practical tips for living with hyperopia:
- Take Breaks During Close-Up Work
Since hyperopic eyes have to work harder to focus on nearby objects, prolonged reading or screen time can cause eye strain or headaches. Follow the 20-20-20 rule: every 20 minutes, look at something 20 feet away for at least 20 seconds to relax your eye muscles. - Keep Your Prescription Updated
Hyperopia can become more noticeable with age, especially after 40, when the eye naturally loses focusing flexibility (presbyopia). Regular eye exams help ensure your glasses or contact lenses are appropriately adjusted, reducing strain and improving comfort for near tasks. - Good Lighting Makes a Difference
Well-lit environments can ease the effort needed to focus up close. Whether you’re reading, working on a screen, or doing a hobby like sewing, ensure you have sufficient lighting to reduce visual fatigue. - Consider Your Vision Correction Options
Laser procedures such as LASIK or PRK can correct farsightedness by reshaping the cornea to focus light properly on the retina. For those over 40, PresbyLASIK or lens-based options may also be suitable. A personalised consultation will help you explore the best path forward.
Astigmatism
Astigmatism is caused by an irregularly shaped cornea or lens that prevents light from focusing evenly. It can cause blurred vision at all distances.
Common symptoms:
- Distorted or wavy vision
- Trouble seeing clearly at night
Four practical tips for living with astigmatism:
- Choose the Right Correction
Ensure your glasses or contact lenses are specifically prescribed for astigmatism. Toric lenses (for contacts) are designed to address the irregular curvature of the cornea, offering clearer vision and reducing symptoms like headaches and eye strain. - Be Mindful of Night Vision
Astigmatism can cause glare, halos, and starbursts around lights—especially at night. Anti-reflective coatings on glasses or specialised lenses can improve contrast and reduce these effects, making night driving more comfortable. - Use Screens with Care
Extended screen use can worsen blurry vision and eye fatigue in those with astigmatism. Adjust your screen brightness, sit at an appropriate distance (about arm’s length), and take regular visual breaks to reduce digital eye strain. - Consider Modern Vision Correction Options
Many forms of astigmatism can now be corrected with custom LASIK, PRK, or toric ICLs, offering sharp, balanced vision without the need for glasses or specialised contacts. Advanced diagnostics ensure your treatment is tailored to the exact shape of your eye.
Presbyopia
Presbyopia is age-related and typically begins around age 40. It reduces your ability to focus on close objects due to a loss of flexibility in the eye’s lens. Unlike other refractive errors, presbyopia affects everyone eventually—even those who’ve never needed glasses before start to rely on reading glasses.
Common symptoms:
- Needing to hold reading material at arm’s length
- Difficulty reading small print
Four practical tips for living with presbyopia:
- Adjust Your Lighting and Text Size
As near vision becomes more difficult, ensure your environment is well-lit—especially when reading or doing close-up work. Increasing font sizes on your phone, computer, or e-reader can also reduce eye strain and make tasks more comfortable. - Use the Right Pair for the Task
Many people with presbyopia benefit from having multiple vision aids—such as reading glasses for close work, and multifocal or progressive lenses for everyday use. Discuss your lifestyle with your optometrist or ophthalmologist to find the most suitable options. - Forgot Your Reading Glasses?
Use your smartphone’s camera to zoom in on small print—whether it’s a restaurant menu or price tag in a shop. The magnification feature can be a quick and discreet solution when your readers aren’t within reach. - Consider Vision Correction Options
Presbyopia is age-related and progressive, but there are advanced solutions beyond reading glasses, including PresbyLASIK, multifocal intraocular lenses, and Allotex corneal inlays. If you’re seeking long-term freedom from glasses, a consultation with a refractive surgeon can help determine the best option for your needs.
How Are Refractive Errors Diagnosed?
Refractive errors are diagnosed through a comprehensive eye examination performed by an optometrist. The assessment typically includes:
- Visual acuity testing (reading charts at different distances)
- Refraction testing using lenses to determine the correct prescription
- Keratometry or corneal topography to measure the curvature of the cornea
- Retinoscopy to evaluate how light reflects from the retina
These tests help identify whether a person has myopia (nearsightedness), hyperopia (farsightedness), astigmatism, presbyopia, or a combination of these.
When Should You Be Screened for Eye Diseases By an Optometrist?
Routine vision screening is important at all stages of life, even if you don’t notice any symptoms:
- Children:
First screening eye exam is recommended at 6–12 months (usually done by the paediatrician), then at least once between 3–5 years, and again before starting school.
Thereafter, every 1–2 years, especially if vision problems or learning difficulties are suspected. - Adults 18–39 years:
Every 2 years if asymptomatic and low-risk. Annual check-ups are advised if you wear glasses or contact lenses. - Adults 40–64 years:
Annual eye exams are recommended, as this is the age when presbyopia and other age-related changes and eye diseases like glaucoma typically begin. - 65 years and older:
Yearly screenings are essential to monitor for refractive changes, cataracts, and other eye conditions associated with ageing.
Early detection enables timely treatment of eye conditions to prevent vision loss, and correcting refractive errors early can significantly reduce visual disability and improve quality of life.
Treatment Options for Refractive Errors
Depending on the refractive error and patient preference, treatment may include:
- Spectacles (glasses)
- Contact lenses
- Laser vision correction (e.g., LASIK, PRK)
- Lens-based surgery (e.g., implantable contact lenses, refractive lens exchange, refractive cataract surgery)
Compare glasses, contact lenses and LASIK
Visual Clarity
Glasses
Provides clear central vision; peripheral vision may be limited due to frame edges.
Contact Lenses
Offers a wider field of vision as lenses move with the eye.
LASIK Surgery
Delivers clear vision across the entire visual field by reshaping the cornea.
Convenience
Glasses
Easy to put on and remove; no direct contact with the eyes.
Contact Lenses
Requires daily insertion, removal, and cleaning; involves direct eye contact.
LASIK Surgery
One-time procedure with a short recovery period; eliminates daily maintenance.
Maintenance
Glasses
Needs regular cleaning to prevent smudges and scratches; frames may require adjustments.
Contact Lenses
Demands strict hygiene practices to avoid infections; lenses need proper storage and timely replacement.
LASIK Surgery
Minimal post-operative care; follow-up visits are essential to monitor healing.
Cost Over Time
Glasses
Initial cost can be moderate to high; replacement needed if prescription changes or frames are damaged.
Contact Lenses
Ongoing expenses for lens replacements and cleaning solutions; costs accumulate over time.
LASIK Surgery
Higher upfront cost; considered cost-effective in the long run due to the elimination of recurring expenses.
Aesthetic Impact
Glasses
Available in various styles; can be a fashion statement but may alter facial appearance.
Contact Lenses
Invisible; does not affect appearance.
LASIK Surgery
No impact on appearance; no need for corrective eyewear post-surgery.
Activity Suitability
Glasses
May be inconvenient during physical activities; risk of slipping, falling off or breaking.
Contact Lenses
Suitable for sports and active lifestyles; no obstruction during movement. Not suitable for water sports.
LASIK Surgery
Ideal for active individuals; swimming resumed 1 month after surgery; PRK may be considered for contact sports participants.
Risk Factors
Glasses
Minimal health risks; potential for lens scratches or frame breakage.
Contact Lenses
Risk of eye infections, dry eyes, or corneal scars. Contact lens intolerance.
LASIK Surgery
Post-operative risks include dry eyes, glare, or halos that usually improve over time; complications are rare with modern techniques.
Reversibility
Glasses
Easily changeable; can switch styles or prescriptions as needed.
Contact Lenses
Flexible; can discontinue use at any time.
LASIK Surgery
Permanent vision correction.
Suitability
Glasses
Suitable for most individuals, including those with certain eye conditions.
Contact Lenses
Not recommended for individuals with specific eye health issues; requires a prescription.
LASIK Surgery
Not everyone is a candidate; suitability determined through comprehensive eye examination and consultation with an ophthalmologist.
Note: It’s essential to consult with an eye care professional to determine the most suitable vision correction method based on individual needs, lifestyle, and eye health.
When to Consider Vision Correction Surgery
Spectacles remain the safest way to correct refractive errors, as they involve no medical intervention. However, some individuals may seek greater freedom due to lifestyle needs—especially in active or high-risk environments where glasses can be impractical, damaged, or even hazardous. If you’re already relying on contact lenses for visual freedom, it’s worth noting that sight-threatening corneal infections occur up to 10 times more frequently in contact lens wearers compared to those who undergo LASIK. Patients who experience repeated infections or contact lens intolerance may benefit from exploring permanent vision correction. If you’re considering life without visual aids, laser vision correction or lens-based procedures may be a logical next step.
Ideal candidates:
- Have a stable prescription:
If your glasses or contact lens prescription has changed by more than 1 diopter (1D) in the past year, it may indicate corneal disease or, in younger patients (ages 18–22), progressive myopia. - You are older than 18
Ages 18 to 40: LASIK is ideal for correcting vision during this stage.
Over 40: As presbyopia (age-related near vision loss) begins to develop, PresbyLASIK is a great option to ensure you remain less dependent on reading glasses.
Around 55 and beyond: Many people start developing cataracts, at which point lens exchange or cataract surgery with multifocal lenses can provide long-term spectacle independence. - You are not pregnant or breastfeeding:
Hormones during pregnancy causes temporary changes in the cornea which may influence your vision whether you had LASIK or not.
A few months after delivering your baby your vision should return to normal. You can have LASIK before you get pregnant and a few months after pregnancy and breastfeeding but not during pregnancy. - Do not have contraindications like uncontrolled dry eye or active eye disease
- You are not pregnant or breastfeeding.
Hormones during pregnancy causes temporary changes in the cornea which may influence your vision whether you had LASIK or not. A few months after delivering your baby your vision should return to normal. You can have LASIK before you get pregnant and a few months after pregnancy and breastfeeding but not during pregnancy.
A consultation with a refractive surgeon is required to confirm your suitability and choose the safest and most effective approach for your vision needs.
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Conclusion
If you’re seeking freedom from glasses or reading aids, understanding your refractive error is the first step. For those interested in vision correction surgery, a consultation with a refractive surgeon is essential to assess your eyes and create a personalised treatment plan. This ensures the safest and most effective path toward long-term spectacle independence.
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Glasses remain a safe option as they do not involve any medical procedure. Vision correction procedures are lifestyle options for those seeking unaided vision and may not be suitable if you are content with wearing glasses. Always consult your refractive surgeon for personalised recommendations.