Contact lens technology has advanced in leaps and bounds over the years. They have come a long way since the first hard contact lenses of the 1960s and 1970s, and there is now a wide variety of contact lenses that are made to suit nearly any need.
Contact lenses vary not only in length of use and change frequency (daily wear, weekly wear, extended wear, monthly disposable) but also in shape and function (astigmatism, bifocal, single vision, dry eye), so it is important to know what options are available. Below are some guidelines and descriptions that may help you determine which contact lenses best match your lifestyle and vision needs.
Contact Lenses by Change Frequency
While some contact lenses are meant to be worn for just one day, there are some that are made to be used for an entire week or longer. Below you will find information regarding contact lenses with different wear and change schedules.
Dailies: Daily disposal contact lenses are discarded every night and replaced every morning. Daily disposable contact lenses are ideal for people with sensitive eyes because they are replaced every day. They do not accumulate the same bacterial and dirt build-up to which other contacts are prone, and they require much less care because they do need to be washed or stored over night.
Weeklies: Like daily disposable contact lenses, weekly disposable contact lenses are made to last a short period of time; however, they do need to be disinfected and stored every night. They are made to be worn for a week and then replaced with a fresh pair. They, like daily disposable contacts, offer a comfortable and fresh feeling because they are frequently replaced.
Monthly Disposable: Monthly disposable contact lenses are very common. They are perhaps even the most common style of contact lenses. They should be changed every night, disinfected with a solution, and stored in a proper receptacle. Monthly disposable contact lenses are safe to wear and provide clear vision for one month.
Extended Wear: Extended wear contact lenses are typically those that can be worn continuously for up to seven days and six nights. Some extended wear contact lenses, namely those made with a silicone hydrogel, can be worn for up to thirty days straight. Extended wear contact lenses have a high oxygen permeability, which means they allow oxygen to pass through them into the cornea. Extended wear contact lenses are best for people who live a highly active or unpredictable lifestyle that may not allow them to remove their contact lenses every night. They are also ideal for people with binocular vision abnormalities and those with especially bad vision who want to be able to see clearly at all times, even when waking up at night or first thing in the morning. Extended wear contacts lenses are typically worn for six days and nights and then stored in a contact lens case for cleaning while the eyes are allowed to rest. It is important to check with and adhere to the wear schedule for each brand and type of extended wear contact lenses as it can differ from brand to brand.
Specialized Contact Lenses
There are specialized contact lenses that are available for people with very specific vision problems or special optical needs. These include contact lenses for people suffering from dry eyes and for those people with moderate or extreme astigmatism. Below you will find information about specialized contact lenses.
Single-Vision Lenses: Single vision contact lenses are made with a single prescription on each lens.
Astigmatism / Toric: Astigmatism is a defect of the eye which is caused by either an irregular (also called "toric") curvature of the cornea or by corneal scarring. Generally, people with astigmatism have a more oblong, rather than round, shaped cornea. The condition causes blurry vision, makes it difficult for people to see fine detail, and may cause vertical lines to appear tilted. People with astigmatism require specialized contact lenses, called toric lenses, which are made with two different corrective powers. And while regular contact lenses can rotate in the eye without affecting vision, toric lenses need to remain centered in order to provide accurate vision.
Toric XR: Toric XR (extended range) contact lenses are available for people whose prescription is outside the parameters of regular toric lenses.
Presbyopia / Bifocal / Multifocal: Presbyopia, like gray hair and wrinkles, is thought to be caused by aging. While the exact physiology behind presbyopia is not fully understood, it is believed to be related to a loss of elasticity of the crystalline lens. Symptoms of presbyopia include: difficulty reading fine print, eyestrain when reading for long periods of time, and momentary blurred vision when transitioning between different viewing distances. There are special bifocal and multifocal contact lenses made to correct this problem. Bifocal and multifocal contact lenses are made with two or more prescriptions in each lens, which allows people to see clearly both near and far.
Dry Eye: Dry eyes and eye discomfort have made it difficult for many people to wear contact lenses. There is a wide variety of contact lenses made specifically to help with this condition. Contact lenses for dry eyes generally have high oxygen permeability are made with a higher percentage of hydrophilic, or “water-loving”, material. This material not only holds onto water but in many cases can attract it, allowing the eye to feel moisturized and comfortable.
Change Eye Color: Colored contact lenses have been popular cosmetic accessories for many years. Colored contact lenses are available with or without a prescription but do need to be fit by an optometrist or ophthalmologist. While there are limitations, colored contact lenses can change the appearance of nearly any eye color.