Specialty Contact Lenses

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Every patient is different and so are their eyes. This means that there need to be different types of contact lenses to suit each individual. Some patients have corneal abnormalities which mean that conventional lenses won’t sit comfortably on the surface of their eyes, while others suffer from eye conditions that mean normal contact lenses won’t be comfortable or could irritate their eyes. 

As you may have guessed from the name, specialty contact lenses are unconventional contacts that are designed for patients that regular contacts might not be suitable. Here are some of the main types of speciality contact lenses and who they are recommended for. 

Who might be a good patient for specialty contact lenses?

Some of the patients that might benefit from specialty contact lenses include those who:

• have been diagnosed with dry eye syndrome

• have corneal scarring

• have been diagnosed with keratoconus, a condition characterized by the bulging of the cornea

• suffer from strabismus, a condition where the patient has an eye that turns in or out relative to the other

• have suffered an injury to the eye

• suffer from a peripheral corneal thinning disorder

• are intolerant to other types of lenses

Your eye doctor or contact lens provider will be able to tell you if you need specialty contact lenses and if so, which lenses would be best based on your individual requirements. 
 

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Rigid Gas-Permeable Lenses

Also known as RGP lenses, these are made from a special material that allows oxygen to pass through them and reach the surface of the eyes. This helps to keep the eyes hydrated and comfortable, making these lenses easier to wear, especially for patients who suffer from dry eyes. Dry eyes aren’t just a symptom, but a very real condition, characterized by dry, stiff, and uncomfortable eyes, blurred vision, and eye fatigue. RGP lenses are more rigid than soft lenses, and this helps to keep them stable and secure on the eyes so that patients can enjoy sharper vision. They also help the cornea to maintain its shape, which helps to minimize the effects of some corneal abnormalities. 

Scleral Contact Lenses

What are scleral lenses?

Scleral contact lenses get their name from the fact that, unlike regular contacts, they vault over the entire corneal surface and rest on the white part of the eye, which is called the sclera. This makes them larger than standard contacts, which in turn provides a variety of benefits. Their size makes them easier to handle and more stable when on the eye, which in turn provides the patient with sharper and more reliable vision. They are also less likely to become dislodged and come out. 

Scleral contact lenses are also gas permeable, which means that oxygen can pass right through them and reach the surface of the eyes. This is important for comfort, particularly for patients who experience dry eyes. The gap that is created between the back of the contact lens and the front surface of the eye can also trap tear film, acting as a fluid reservoir which will keep the eyes moist and healthy. 
 

Types of scleral lenses

Within scleral lenses there are several different sizes to choose between. These are based on where the lenses meet the surface of the eye and are as follows:

• Full scleral lenses: the largest type, they provide the greatest amount of clearance between the cornea and lens and rest on the outer sclera. 

• Mini scleral lenses: the mid-size variety, make contact with the eye on the anterior sclera. 

• Semi-scleral lenses: although larger than conventional lenses, they are not huge, and the edge of the contact lens rests on the junction between the cornea and the sclera. 

Your scleral lens provider will be able to make a recommendation as to the correct size for you, which will be based on your individual requirements. 
 

Who are scleral lenses recommended for?

Although technically anyone can wear and benefit from scleral lenses, they are a particularly good option for patients who have eye conditions or irregularities that for which regular contacts are not suitable. This includes patients with:

• Dye eye syndrome. Contact lenses float on a fine layer of tear film, which keeps them comfortable and in position. Patients with dry eye syndrome either do not have enough natural tear film, or what they do have drains away too quickly. This canmake wearing regular contact lenses difficult and uncomfortable. However, the design of scleral lenses keeps moisture on the surface of the eyes, eliminating some of the effects of dry eyes. This makes scleral lenses a great choice for patients with dry eyes. 

• Irregular corneas. The cornea is the clear dome that covers the front part of the eye and many people have a cornea that is a slightly, or significantly, irregular shape. This causes light to be refracted incorrectly when it enters our eyes, triggering vision problems. Issues arising from irregularly shaped corneas cannot be completely corrected using glasses or conventional contact lenses. Therefore, scleral lenses, which provide sharper and more accurate vision, are recommended. 

Limbal Fit Contact Lenses

Limbal contact lenses are another type of specialty lens that falls between rigid gas-permeable lenses and scleral varieties in terms of their size. Their larger overall diameter helps to increase their stability on the surface of your eyes. They also offer minimal interference with the eyelids, which helps to ensure comfort and clarity of your vision.

Hybrid Contact Lenses

Hybrid contact lenses are a combination of both soft and gas-permeable contact lenses, giving patients the opportunity to enjoy the best parts of both designs. The middle part of hybrid lenses is made from gas-permeable material that lets oxygen pass through to the eyes. However, the gas-permeable part of the lens is more rigid, and this firmer center gives the lens greater stability and the patient enhanced clarity. The RGP portion of the lens also helps to trap a tear film between the cornea and the lens so that the eye remains hydrated. Meanwhile, the outer edge of hybrid lenses is a soft lens skirt. This means that patients don’t have to deal with the hard edges associated with RGP lenses that may be uncomfortable. Instead, the comfort levels that patients experience are more like wearing fully soft lenses. 

For more information about specialty contact lenses, don’t hesitate to speak to our dedicated eye care team.