Contact Lenses have come a long way since their invention in 1887. Today, almost everyone who needs vision correction is able to be fit in contact lenses. When your contact lens fitting is done at The Eye Center the first thing we will decide is which lens material is most appropriate for you. Soft lenses are made from plastic material that have some water content, these are called “hydrogels”. In 2002 silicone was added to hydrogel material. The silicone content allows more oxygen to reach the cornea, the clear covering of the eye the contact lens is applied worn on. These contact lenses are called “silicone hydrogels” and are the most popular lenses on the market today. Hydrogels and silicone hydrogels can be replaced every day, weekly, bi-weekly, monthly, quarterly, or yearly. Many of these lenses are available in cosmetic colors that enhance or change your eye color. Tinted soft contact lenses can also be used for patients that are extremely light-sensitive. Some soft contact lenses are FDA approved for overnight or extended wear, and while this is appropriate for some patients, we usually do not recommend it, as sleeping in your contact lenses increases your risk of an eye infection six times. Daily disposables are worn for one day and then thrown away after wear. These are the safest and healthiest lens option and are preferred for anyone who is very active, works outside, or suffers from dry eye or eye allergies, and children. Daily disposables were invented because many patients had trouble tolerating a lens worn more than a week or sometimes even a few days.
Soft contact lenses are also available in a variety of designs. These lenses can correct nearsightedness, farsightedness, astigmatism, and presbyopia. Astigmatism is a vision problem where the curvature of the cornea and/or lens inside the eye is more football or egg-shaped, rather than being perfectly round like a basketball. Astigmatism correcting lenses are usually called “toric”. Presbyopia refers to a vision problem where you require correction for reading only or a different amount of prescription for reading and up-close vision than what is needed for the distance. Presbyopia typically affects patients over the age of 40. Contact lens options for patients with presbyopia include multifocal lenses or a technique called monovision. When we use the monovision technique we correct one eye, usually your more dominant eye, for distance vision and we correct your non-dominant eye for intermediate/computer vision or near/reading vision. Your brain learns to use the image from whichever eye is most focused and clear. Sometimes monovision gives slightly more crisp or clear vision than multifocal lenses however, it does cause a decrease in in-depth perception (using both eyes together). Multifocal lenses include distance and near prescriptions in both eyes. There are many different multifocal designs but most use a “bullseye” design where the distance or near prescription is in the centermost portion of the lens and the distance and near correction alternates throughout many rings of the design. We call this “simultaneous vision” where your brain learns to utilize the portion of the lens that is most clear for the needed viewing distance. All contact lenses, but especially, torics, monovision, and multifocal lenses may require more than one visit to get your optimal correction in your everyday situations.
Specialty contact lenses are available for patients that have severe astigmatism, eye disease, or patients who may have had an eye injury. These lenses include gas permeable contact lenses, hybrid contact lenses, scleral contact lenses, light adaptive lenses, and prosthetic lenses. Gas permeable contact lenses, sometimes referred to as RGP’s or GP lenses are also made of a plastic polymer material but this material is more stiff or rigid than soft contact lenses. These lenses are smaller than soft contact lenses and rest within the boundary of the cornea. The benefit of this stiffer material is that it maintains it’s round curvature when placed on the cornea. This material can normalize the corneal shape in patients with moderate to severe astigmatism and many times can better compensate for it providing more crisp and clear vision. Sometimes, these more rigid materials are not as comfortable as soft lenses but usually, a patient adapts within 2 weeks of lens wear. Sometimes we will “piggyback” a rigid lens on the top of a soft contact lens to optimize the fit and comfort of these lenses. If a patient is unable to adapt to GP’s, another option is a “hybrid” lens. This lens has a center GP with a soft lens skirt all the way around it. So it gives the vision of a GP with the comfort more similar to a soft contact lens. Yet another option for patients requiring specialty lenses is a scleral lens. These lenses are made of GP material yet they are much larger than GP lenses and they rest beyond the cornea on the white part of the eye called the sclera. These lenses are filled with a preservative-free saline solution which can be very beneficial for patients with dry eye for which other treatments have not been helpful. These lenses are sometimes the last option for patients with the eye disease keratoconus and have greatly decreased the rate and need for corneal transplants in these patients. Scleral lenses are also very, very comfortable! In patients who have suffered an eye injury that has cosmetically affected the appearance of one or both eyes, we can fit a prosthetic colored contact lens to mask the injury and correct vision as much as possible. All of the above specialty contact lenses are generally replaced every 6 to 12 months.
All contact lenses contain some UV protection. Some contain more UV protection than others and will be taken into consideration during your contact lens fitting depending on your special circumstances. Patients who work outside, are light-sensitive or suffer from migraines that are triggered by bright lights may do well with “light adaptive” contacts. These lenses change to a tint similar to that of sunglasses when you are outside in bright light or are exposed to bright light. These lenses are available in a two week replaced disposable.
We also have theatrical, novelty, and special effects lenses for patients who are interested. Whatever your contact lens needs are, the optometric physicians at The Eye Center are your contact lens specialists and we look forward to discussing your options with you to maximize your vision!