A contact lens prescription is not your spectacle number

What a fitting actually involves

Four things are assessed, and each one can rule a lens out.

• Eye health: the surface, lids and cornea checked for infection, dryness or damage first
• Corneal measurement: the curvature of your cornea, which decides the base curve of the lens
• Pupil and iris measurement: sizes the optical zone correctly
• Tear film evaluation: whether your eyes make enough good quality tear to keep a lens comfortable all day

Then a trial, then a follow up

A trial lens goes in and is checked on the eye for fit, movement and comfort, and your vision is measured with it in. You wear it and report back. Only then is a final prescription issued. Buying lenses from a spectacle number and skipping this is how people end up with red eyes and abandoned boxes.

What is available

Which type suits you depends on your eyes, how many hours you wear them, and how much you want to look after them.

• Daily disposables: no cleaning, lowest infection risk, best for part time wear and sport
• Bi-weekly and monthly: more economical for daily wearers, and needs proper cleaning discipline
• Toric lenses: for astigmatism, weighted to stay oriented on the eye
• Multifocal lenses: distance and near in one lens, for people over about forty
• Coloured lenses: cosmetic, and still medical devices that need fitting
• Specialty lenses: for irregular corneas and eyes that ordinary soft lenses will not fit

The hygiene part that actually matters

Wash and dry your hands before touching a lens. Never rinse a lens or a case in tap water. Replace the solution every time rather than topping it up. Replace the case every three months. Take lenses out before you sleep unless you have been specifically fitted for overnight wear. Never wear a lens in a red or painful eye, and never swim in lenses. Microbial keratitis is rare and it is sight threatening, and almost every case traces back to one of these.

Come in the same day if

An eye becomes red and painful while wearing lenses, your vision drops, or light becomes hard to tolerate. Take the lens out, do not put it back in, and call +91 82963 57123.

Questions people ask about this