Types of Contact Lenses

Soft Lenses

Soft contact lenses come in a wide variety of materials, fittings, powers and designs to correct almost all types of vision. Soft lenses incorporate water, much like a sponge, and must be kept in contact lens solution to prevent them from drying out.

Advances in materials have led to a new generation of soft contact lenses called silicone hydrogels which allow much more oxygen to pass through to the cornea, making them healthier for the eye. Originally intended for extended wear, these materials are now used for all types of soft lenses.  .

Replacement may be daily, two-weekly, monthly, or in some cases three-monthly, six-monthly or less often. The lenses may be used on a daily-wear basis or sometimes for up to 30 days of extended (or ‘continuous’) wear. The most commonly fitted soft lenses in the UK are daily wear, monthly replacement lenses, followed by daily disposable single-use lenses, worn for a day then thrown away.

Rigid or ‘Rigid Gas Permeable’ lenses

RGP contact lenses have been available for longer than soft contact lenses, although many improvements have been made over this time to allow more oxygen to pass through the material.

Rigid contact lenses come in an extensive range of materials, fittings, power and designs. Despite a decline in the use of rigid lenses, some contact lens practitioners believe RGP lenses provide a healthier option for long-term, full-time wear than soft contact lenses.

They are thought to be better at correcting irregularly shaped eyes than soft lenses and are also more durable so are usually replaced every six or 12 months, making them a very cost-effective option.

Contact lenses for astigmatism (‘toric’ lenses), bifocal and multifocal lenses are all available in gas permeable materials. RGP lenses are normally used for daily wear but a technique called orthokeratology (‘corneal reshaping’ or ‘overnight vision correction’) is gaining in popularity. This is where specially designed gas permeable lenses are worn overnight and removed during the day. The aim is alter the shape of the cornea in order to reduce or correct short sigh