Myopia: why distant things look blurry
A practical introduction to nearsightedness and the questions to bring to an eye exam.
THE CLEAR VISION GUIDE
Encyclopedia
Explore practical guides to vision, lens materials, coatings, progressive lenses, contact care and buying glasses, with links to original sources.
01
Vision basics
Understand what your eyes need.
02Lens materials
Look beyond the index number.
03Coatings & light
Separate useful features from claims.
04Progressive lenses
Find your way from near to far.
05Contact lens care
Everyday habits for safer wear.
06Buying glasses
Ask better questions at your appointment.
All guides
Presbyopia is not the same as farsightedness
Why near vision changes with age, including when you already wear distance glasses.
Single vision, bifocal or progressive?
Start with the distances you need to see, then discuss a lens design.
Lens index: what 1.50, 1.60 and 1.67 mean
Higher index can change thickness, but it is only one part of choosing a lens.
Why frame size changes lens thickness
Your prescription, frame shape and fitting measurements work together.
Lens materials: more than thinness
Discuss weight, optical properties and impact needs as separate requirements.
Do blue-light glasses help with screen strain?
What a Cochrane review does—and does not—tell us about blue-light filtering lenses.
Photochromic lenses and driving: check the variant
Different light-reactive lenses have different uses, especially behind a windscreen.
Sunglasses: check UV protection first
A dark appearance is not the same thing as a verified UV protection claim.
How progressive lens zones work
Understand the journey between distance, intermediate and reading vision.
Office lenses: begin with your monitor distance
A work-specific design needs a clear description of your workspace.
What does a personalised progressive lens mean?
Compare the measurements and design process, not just the premium label.
Keep water away from contact lenses
Why showering, swimming and lens rinsing need different habits.
Contact lens cleaning: fresh solution matters
Reusable lenses and their storage case both need an appropriate care routine.
Contact lens discomfort: when to stop wearing
Pain or unusual redness calls for attention, not another trial of the same lens.
Read your glasses prescription without guessing
A guide to SPH, CYL, AXIS, ADD and the fitting measurements recorded alongside them.
How to compare two lens quotes fairly
Get the exact design, material and service terms in writing.
Collecting new glasses: a practical checklist
Check the order, fit and everyday tasks before leaving the practice.
Astigmatism: blur, ghosting and the eye exam
Understand why focus can be uneven and what to tell your practitioner before changing glasses.
Farsightedness: why near work can be tiring
Hyperopia can be easy to overlook. Learn how an eye exam differs from simply checking distant letters.
Dry eyes and blur that comes and goes
A changing image is not always a reason to buy stronger lenses. Start with the tear film and symptoms.
New flashes or floaters: when it is urgent
Know the warning signs that should not wait for a routine glasses appointment.
Children’s vision screening: what happens next?
Understand a screening result, the need for follow-up and what to bring to a child’s eye appointment.
Screen eye strain: a better desk routine
Look at viewing distance, glare, breaks and your actual prescription before adding another lens feature.
Polycarbonate and Trivex: when impact matters
Compare a lens material with the requirements of the whole pair of glasses, especially for active use.
Abbe value: why some lenses show colour fringes
Understand dispersion without turning one material number into a universal quality score.
Aspheric lenses: design, appearance and fit
Learn what a flatter lens design can change and which questions still need an individual answer.
Anti-reflective coatings: what are you paying for?
Separate surface reflections, scratch resistance and easy-clean features when comparing coatings.
How to clean glasses without damaging the coating
A daily routine for lenses, cloths and storage, with a clear distinction from contact lens care.
Polarised sunglasses: glare relief and screen limits
Understand where polarisation helps and test your actual dashboard or phone before buying.
Night driving glare: check vision before buying a tint
Why darker is not automatically better at night, and what to ask about your driving glasses.
First progressive glasses: making the change
Learn the viewing zones in familiar surroundings and know when to ask for a fitting check.
Progressive fitting height: why the frame matters
A frame’s appearance is only part of the choice when several viewing zones must fit inside it.
Ready-made reading glasses: useful spare or poor match?
Understand equal powers, astigmatism and why readers do not replace a personalised eye examination.
Daily disposable or reusable contacts: two schedules
Wearing hours and replacement dates are different decisions. Learn what to confirm for your own lenses.
Can you nap in contact lenses?
Why a short nap still belongs in the conversation about overnight wear and infection risk.
Peroxide lens solution: neutralisation is essential
Understand the special case, waiting time and why this solution cannot be used like ordinary rinsing fluid.
Travelling with contacts: pack a backup plan
A travel checklist for supplies, sleep, swimming and situations where glasses are the easier option.
Buying glasses online: check the fitting plan
A clear prescription is only one part of ordering. Check measurements, adjustment and the return process.
Pupillary distance: more than a checkout field
Learn why lens position belongs with frame choice and why unclear measurements should be checked.
Sports glasses: protection is a whole-pair decision
Match the frame, lens and activity instead of relying on a tough-material label alone.
Glasses slipping or leaving marks: check the fit
Bridge support, sides and wearing position can matter as much as a frame’s stated size.