A contact lens is a corrective, cosmetic or therapeutic lens usually placed onto the front surface of the eye. Contact lenses are predominately used to correct vision and offer many advantages over glasses.
People choose to wear contact lenses for some or all of the following reasons
- Cosmetic – virtually invisible to the observer
- No steaming or fogging in rainy weather
- Wider field of view
- Safer for sport
- To obtain the best vision possible in certain conditions where spectacles cannot do so e.g. keratoconus
- To temporarily correct short sightedness without spectacles – orthokeratology
Contact lenses are used to correct the same conditions that spectacles correct.
PMMA
Lenses made from a rigid plastic material were the original contact lens. They are pretty much obsolete now due to their poor ability to allow oxygen to pass through to the cornea.
Gas-permeable lenses
These lenses are also known as “RGPs.” They are newer rigid or “hard” lenses made of plastics combined with other materials, which allow oxygen in the air to pass directly through the lens.
Replacement Schedule: RGP lenses are usually replaced on an annual basis. However if they are well cared for and maintained they can last for longer periods.
Soft contact lenses
These lenses are made of plastic materials that incorporate water and in some cases silicone. The addition of silicone to contact lens materials allows more oxygen to reach the cornea.
Soft Contact Lens Replacement : Soft contact lenses are available in the following replacement designs depending on the brand.
- Daily
- Two weekly
- Monthly
- Three monthly
- Annual
Extended wear contact lenses
Extended wear contact lenses are made of material that is so permeable to oxygen that they are safe to wear even with the eyes closed i.e. while asleep.
Replacement schedules for extended wear lenses are usually on a weekly, two weekly or monthly basis depending on the material and manufacturer guidelines.
Specialised contact lenses
Although every case is unique, some ocular conditions require specialised contact lens fittings.
Using Rose-K and the new ClearKone contact lenses available , we are able to provide such a service to patients with irregular shaped (or kerataconic) corneas.
CHECK UPS
Regular contact lens check ups are vital for all contact lens wearers. Although your lenses may feel great and your vision is sharp, you still need to have your lenses checked.
It is recommended that you have your lenses checked at least once a year and more regularly if recommended by your Contact Lens Practitioner.
Remember to remove your lenses and consult with your contact-lens practitioner if you experience any of the following symptoms while wearing your lenses ;
- Blurred vision
- Pain
- Red eye
- Discharge
- Discomfort
