Understanding Your Contact Lens Prescription
Your contact lens prescription is not the same as your glasses prescription. Learn what BC, DIA, SPH, CYL, and AXIS mean.
Types of Contact Lenses Explained
Daily, fortnightly, monthly, toric, multifocal — what the differences mean and which schedule suits your eyes and lifestyle.
Contact lenses are available in more designs and schedules than most people realise. The replacement schedule — how often you discard and replace your lens — affects your daily routine, your risk of complications, and your running costs. Beyond that, specialist lens designs exist to correct astigmatism, presbyopia, and even for cosmetic use. Understanding the differences helps you have a better conversation with your optometrist and make a more informed choice.
Replacement Schedules
Most soft contact lenses worn in Australia are replaced on one of three schedules. The schedule determines how long you can wear a single pair of lenses before discarding them — not how many hours per day you wear them.
Daily disposables
Worn once and discarded at the end of the day. A fresh, sterile lens every morning with no cleaning routine. Daily disposables carry the lowest risk of lens-related complications and are the recommended starting point for new wearers.1
Recommended for new wearersFortnightly lenses
Replaced every two weeks from the date of first opening. Require nightly removal and cleaning with a multipurpose or hydrogen peroxide solution. A natural step up once you are comfortable with lens handling and care.
IntermediateMonthly lenses
Replaced every 30 days from the date of first opening. Require a consistent nightly cleaning and storage routine. Most cost-effective for wearers who use lenses every day without exception.
Cost-effective for daily wearersImportant
Never extend the wear period of a lens beyond its prescribed replacement schedule. Wearing a monthly lens for six weeks, or a daily disposable for two days, significantly increases the risk of protein deposit build-up, reduced oxygen transmission, and serious eye infection.
Specialist Lens Designs
Beyond replacement schedule, lenses are also designed to address specific vision conditions. All specialist lenses require an up-to-date prescription and a fitting by a registered optometrist.
Toric lenses
Designed to correct astigmatism — an irregularity in the curvature of the cornea or lens that causes blurred or distorted vision. Toric lenses have different powers in different meridians and are weighted to stay stable on the eye. Available in daily, fortnightly, and monthly schedules.
For astigmatismMultifocal lenses
Designed to correct presbyopia — the gradual loss of near-vision focus that typically begins in your early 40s. Multifocal lenses incorporate multiple prescriptions into a single lens, allowing clear vision at both near and far distances.
For presbyopiaColoured lenses
Available with or without vision correction. Coloured lenses that carry no prescription are still classified as medical devices and must be fitted and prescribed by an optometrist — they cannot be safely purchased without a valid fitting. Wearing unfitted coloured lenses carries the same infection risks as any other contact lens.
Cosmetic or correctiveLens Materials
Most modern contact lenses are made from one of two materials. The material affects how much oxygen reaches your cornea during wear, which directly influences comfort and the maximum recommended daily wear time.
Silicone hydrogel
The most widely used material in modern contact lenses. Silicone hydrogel transmits significantly more oxygen to the cornea than conventional hydrogel — typically five to six times more. This supports longer comfortable wear periods and reduces the risk of hypoxia-related complications. Most daily, fortnightly, and monthly lenses from major brands are now silicone hydrogel.
Higher oxygen transmissibilityHydrogel
The original soft lens material, still used in many daily disposable lenses. Conventional hydrogel has lower oxygen transmissibility than silicone hydrogel but remains suitable for standard daily wear schedules. Hydrogel lenses are often softer and may feel more comfortable for wearers with sensitive eyes, and are typically available at a lower cost per lens.
Lower cost, suitable for daily wearHow to Choose the Right Lens Type
The right lens type depends on your prescription, your lifestyle, your daily routine, and your eye health. Your optometrist will recommend a lens type and schedule based on your clinical assessment — not every lens is suitable for every wearer.
As a general starting point: new wearers are almost always best served by daily disposables. They remove the complexity of a cleaning routine, carry the lowest risk of complications, and allow you to focus on getting comfortable with the experience. Wearers who use lenses every day may find monthly lenses more cost-effective once they are experienced with lens handling and hygiene.
Prescription required
Contact lenses should only be ordered online if they have been prescribed by your optometrist and you have previously worn the specific lens. If you are considering a new brand or lens type, request a trial pair from your optometrist before purchasing. Wearing a lens that has not been professionally fitted to your eye can cause discomfort and serious complications.2
Frequently Asked Questions
What is the best type of contact lens for a first-time wearer?
Daily disposable contact lenses are recommended for first-time wearers. They require no cleaning routine, carry the lowest risk of lens-related complications, and simplify the adjustment process. Once you are comfortable with lens handling, your optometrist can advise whether a fortnightly or monthly lens is appropriate for your wearing habits.
Can I wear monthly contact lenses as dailies to save money?
No — you must not wear a monthly lens for a single day and then discard it. Monthly lenses are manufactured with a thicker material designed for 30 days of nightly cleaning and storage cycles. Using one as a daily disposable wastes the lens and does not improve safety. If cost is a concern, speak to your optometrist about the most economical schedule for your wearing frequency.
What type of contact lens do I need if I have astigmatism?
Toric contact lenses are specifically designed to correct astigmatism. They are available in daily, fortnightly, and monthly schedules from all major brands. Your optometrist will prescribe the appropriate toric lens based on your corneal measurements and the degree of astigmatism in your prescription.
Is silicone hydrogel better than hydrogel for contact lenses?
Silicone hydrogel transmits significantly more oxygen to the cornea, which is beneficial for eye health during longer wear periods. Most optometrists recommend silicone hydrogel lenses for daily wear. However, conventional hydrogel lenses remain appropriate for many wearers — particularly those with sensitivities to silicone — and are still widely prescribed. Your optometrist will recommend the right material based on your individual needs.
Contact lens suitability, replacement schedules, and wear times must always be confirmed by your optometrist based on your individual prescription and eye health.
Ready to shop?
Shop by Lens Type
Browse daily disposables, toric lenses, multifocals, and coloured lenses from Acuvue, Alcon, CooperVision, and Bausch + Lomb — with fast Australia-wide delivery.
References
- Centers for Disease Control and Prevention (CDC) — Fast facts on contact lens types. cdc.gov
- American Optometric Association (AOA) — Overview of contact lenses, suitability, and care. aoa.org
- Optometry Australia — Contact lens resource guide. optometry.org.au