- Conditions correctable with lenses
- Lens types
- Replacement, wear and care schedules
- Novelty coloured contact lenses
Almost anyone who wears spectacles can wear contact lenses, including people who require multifocal lenses. New technology means contact lenses are clearer, more comfortable and more convenient than ever; they provide a full field of unobstructed vision, freedom of movement unmatched by spectacles, additional flexibility to take on new activities with crisper vision and are also a great way to update your image.
Whether you are already a contact lens wearer, or are considering contact lenses for the first time, seek professional advice from your optometrist to ensure the correct type, fit, prescription, use and care of your lenses for your eyes and lifestyle.
A corrective contact lens is designed to improve vision. Conditions correctable with contact lenses include:
- Shortsightedness (blurred distance vision)
- Longsightedness (blurry or strained vision)
- Astigmatism (visual distortion)
- Presbyopia (blurred near vision that occurs as we age
Soft contact lenses
- are the most commonly prescribed type of contact lenses (around 90 per cent)
- are generally comfortable to wear, easy to use and are difficult to accidentally dislodge
- correct most types of focusing errors
- can be tinted to enhance or change eye colour
- are made from flexible materials known as hydrogels, made up of part plastic and part water (silicone hydrogel lenses allow even more oxygen to pass through the lens than traditional hydrogel lenses, essential for a healthy cornea)
Soft contact lenses are suitable for people who play indoor and outdoor sports, those who don’t want to wear lenses every day and people with sensitive eyes.
Rigid contact lenses
- can provide better vision than soft lenses for certain higher or more complex prescriptions, as the optics are better controlled
- are more durable than soft lenses and do not need to be replaced as often
- may require some adaptation initially until comfort levels are achieved
- are made from plastics that are less flexible than those used for soft lenses
Rigid contact lenses are suitable for a wider range of correction for shortsightedness, longsightedness and astigmatism.
Association of Malaysian Optometrists advises that contact lenses, regardless of type, tinting, optical power, or intended use, should only be supplied on presentation of a valid prescription.
Different lenses need to be replaced at different times, due to lenses wearing out and in order to maintain good eye health. The length of time the lens may be re-used and how to care for them depends on the type of lens.
Disposable contact lenses
Disposable lenses should be replaced according to their disposable time frame i.e. daily, weekly, two-weekly or monthly.
Disposable lenses are the most commonly prescribed and are an excellent choice health-wise because there is less opportunity for protein and bacteria to build up on them. With daily disposable contact lenses, you won’t even need to disinfect your contact lenses after each use.
Non-extended wear contact lenses
Non-extended wear lenses are applied in the morning and removed in the evening. Lenses should be cleaned and disinfected before being worn again to prevent the collection of residues (proteins and bacteria) that can cause eye infections, and for improved comfort. Lenses are usually cleaned by rubbing between the palm of one hand and a finger, using an appropriate cleaning solution. In some cases disinfection using another type of solution is also required. Your optometrist can advise the best way to clean your contact lenses.
Extended wear contact lenses
Extended wear lenses can be worn continuously (day and night) for up to a certain number of days, usually seven to 30. These lenses allow large amounts of oxygen to pass through to the eye. Only the right type of lenses may be worn while you sleep – always check with your optometrist first. Extended wear contacts are not suitable for everyone; your optometrist can advise if they are suitable for you.
Long wear contact lenses
Planned replacement contact lenses last one to several months. Customised soft contact lenses can last up to a year; conventional rigid contact lenses can last even longer and often only need replacing due to a change in prescription.
Professional care and advice from an optometrist is essential in the prescribing of contact lenses.
Contact lenses must:
- correct any degree of focusing errors;
- fit without causing any injury to the surface of the eye
- move on the surface of the eye
- allow the eyelids to comfortably move over the eye
- not provoke any reaction from the eye
Your optometrist will:
- check the health of your eyes
- measure your degree of focusing error
- discuss your visual and lifestyle needs to determine the best contact lenses for you
- measure the curvature of your eyes to ensure the best contact lens fit
Your optometrist will place a trial lens on your eye to assess the fit and will recommend the most suitable trial lenses. They will teach you how to handle, apply, remove, clean and store your lenses and will recommend a replacement schedule. Your optometrist will usually reassess the lenses after they have been worn for a week or two, in order to make sure they’re fitting and performing properly; they will then provide a preliminary prescription and order your lenses.
Most optometrists encourage contact lens wearers to have eye examinations every 12 months to ensure your prescription and contact lens type are still appropriate and to detect and correct problems early.
After-care appointments are a great opportunity to raise any concerns you may have about your contact lenses. Since a contact lens sits directly on the eye it increases the risk of complications such as eye infections. While serious complications of contact lens wear are rare, regular eye examinations are a good insurance policy. As technologies evolve every year, your optometrist may suggest you upgrade to the latest material or design.
Novelty coloured contact lenses are those which change the appearance of the eyes. Even though they do not contain any optical power, they should still only be supplied on presentation of a valid prescription.