Contact lenses are artificial lenses designed to be worn on the surface of the eyes to correct vision abnormalities such as near-sightedness, farsightedness, and other conditions that cause blurry or distorted vision. Unlike glasses, contact lenses do not change your appearance and provide a clear unobstructed field of vision.
Contact lenses can be made of various materials:
- Soft lenses: Made of a gel-like plastic material containing water and are comfortable to wear. Silicone soft lenses are an advanced type of soft lens that promotes eye health by improving oxygen transmission to the eye.
- Gas permeable lenses: Rigid plastic lenses that permit the passage of oxygen and are designed to produce sharper vision for those with conditions such as astigmatism (irregularly shaped cornea) and presbyopia (age-related rigidity of the lens)
- Hybrid lenses: These have a central zone made of gas permeable rigid plastic for improved vision and a peripheral zone made of soft lens material for improved comfort
The different types of contact lenses include:
- Spherical contact lenses: regular round design prescribed for nearsightedness or farsightedness
- Bifocal contact lenses: have different zones to accommodate near and far vision for presbyopia
- Orthokeratology lenses: reshapes the cornea while sleeping, allowing lens-free daytime wear
- Toric contact lenses: have a feature that allows the lens to rotate and align in the correct orientation to manage astigmatism
Some types of contact lenses need to be removed at night and kept in a storage solution while others are designed for extended wear.
Your doctor will evaluate your eye structure, vision, and tear production and choose the lens material and design that corrects your vision abnormalities and fits your eyes appropriately. Certain conditions such as dry eyes or keratoconus (cone-shaped cornea producing distorted vision) require special lenses. Certain features such as colour can also be incorporated to suit your personal preference. Contact lenses need to be worn, cared for and replaced according to your doctor’s instructions. They do require a period of getting used to and sometimes certain adjustments may need to be made.