Medical lenses

This refers to contact lenses which are designed for medical or therapeutic reasons. These include eye conditions which are described as ‘non-refractive’.

Refractive errors such as short sightedness and long sightedness are treated with corrective lenses. Corrective lenses and cosmetic lenses are discussed separately.

Medical lenses are worn to treat the following conditions:

• Keratitis
• Diseased cornea
• Corneal ulcers
• Dry eyes
• Keratoconus

Keratitis

This is the medical name for an inflammation of the cornea (front part of the eye) which is caused by a variety of reasons. These include a bacterial or viral infection or exposure to UV radiation.

This is characterised by pain and impaired eyesight.

There is a range of treatment available for this which includes a bandage type contact lens which stops the eyelid from rubbing against an already inflamed cornea.

Diseased cornea

This is an umbrella term used to describe a range of conditions which affect the cornea. These include infections, problems caused by a build up of fluid and erosion (wearing away) of the outer layer of the cornea.

Treatment involves the wearing of a bandage contact lens or a type of lens which transfers medication into the affected area.

Corneal ulcers

This is a type of open sore which forms on the cornea and is usually caused by dry eyes, eye injury or an eye infection.

These are treated with anti-bacterial eye drops or ointment or a bandage contact lens.

Dry eyes

This occurs when there is lack of tears produced by the tear ducts which causes the eye to feel gritty, sore and itchy. There may be burning sensation in the eye or the eyes feel generally tired.

The aim is to ensure that the eye is sufficiently lubricated which will prevent these symptoms. Eye drops are one option but another is a custom made contact lens which rests over the white of the eye. This produces a layer of fluid which prevents any drying out of the eye.

Keratoconus

This is a medical term for a degenerative condition which affects the cornea. The cornea becomes thinner and loses it natural shape as a result which distorts the vision.

Contact lenses are often prescribed for this condition. Soft lenses can be worn by people in the early stages of this condition but there are ‘scleral lenses’ designed for this purpose. These are a large type of contact lens – larger than the normal lenses – which leaves a space over the cornea and rests on the white of the eye. This prevents it from touching the cornea and allows fluid to lubricate the eye.

Prosthetic contact lenses

Another type of lens is a prosthetic contact lens which is worn to hide the signs of an illness or injury which has affected the appearance of the eye. These are often coloured so that they match the colour of the other eye which reduces any feelings of self-consciousness.

A prosthetic lens can help to prevent too much light from reaching the retina, thereby minimising any glare. This is known as light sensitivity.

These contact lenses are available as soft lenses or gas permeable lenses and are cared for in the same way as any other type of lens.

Prosthetic lenses can treat the following conditions:

• Double vision
• Lack of colour/pigment in the eye
• Damaged cornea, e.g. injury
• Light sensitivity
• Congenital disorder of the pupil

These lenses work by restoring the appearance of the eye so that it matches the other to give a balanced look. They are used in cases of double vision where they block on of the two images, forcing the brain to concentrate on the one image.

Prosthetic contact lenses are available on prescription only. The usual process is an eye test/exam followed by a contact lens fitting. Close up photos may be taken of your eyes which enable the manufacturer to produce a lens which will fit your eye.

Hard to fit eyes

If none of these solutions work then you may be one of a group of people who are considered to have ‘hard to fit’ eyes. This may sound harsh but it is in fact a term used to describe people who for a variety of reasons are unable to wear normal contact lenses.

This includes people who find it difficult to wear normal contact lenses or have eyes which do not lend themselves to any type of contact lens.

This does not mean that you are ruled out from wearing contact lenses. But what it does mean is talking to a qualified eye practitioner about the options available to you.

So what is likely to qualify you as having eyes that are ‘hard to fit?’

This includes the following eye conditions:

• Astigmatism
• Dry eyes
• Giant papillary conjunctivitis
• Post-refractive eye surgery, e.g. laser eye surgery
• Presbyopia

Astigmatism This is where the cornea (front of the eye) becomes distorted over a period of time, which changes it from the normal spherical (round) shape to an oval shape. This then prevents the retina from focusing properly. The end result is blurred vision.

Dry eyes

This is defined as a lack of lubrication and moisture in the eyes which can cause itchiness, soreness and a gritty feeling in the eye.

Giant papillary conjunctivitis

Conjunctivitis is the name for an inflammation of the eye, leading to the characteristic ‘pink eye’appearance. This is caused by a variety of factors such as bacteria, viruses and foreign bodies.

Giant papillary conjunctivitis often occurs in people who wear soft contact lenses. The eyes become itchy, sore and red bumps may develop underneath the eyelids. The affected person finds it uncomfortable to wear soft contact lenses and has to change to a different type or stop wearing them for short period of time.

Post-refractive eye surgery

This refers to laser eye surgery, e.g. LASEK or LASIK which reshapes the cornea, which improves the ability to focus and eyesight in general. This is often performed on short and long sightedness.

Presbyopia

The name given to a blurring of the vision, especially when viewing objects close to which occurs around the age of 40. This is a normal part of the ageing process in which the lens of the eye becomes thicker and less flexible as a result.

If you are suffering from any of these conditions then it means finding someone who specialises in fitting contact lenses for hard to fit eyes such as yours.