Whether you’re nearsighted, farsighted or affected by astigmatism, contact lenses can remedy your visual shortcomings. If you and your eye care practitioner determine that contact lenses are the right choice for you – there are some contact lens terms that you need to know.
Your Eyes and Vision
Accommodation: Your eyes’ ability to focus at a range of distances.
Astigmatism: The condition in which your lens or cornea is shaped irregularly, like an ellipse. Astigmatism occurs in both farsighted and nearsighted individuals causing blurred vision or the inability to clearly focus.
Our recommendation: Acuvue Oasys for Astigmatism. These two-week disposable lenses with Hydraclear technology provide crisp vision, a comfortable fit and astigmatism correction
Cornea: The curved, front surface of the eye that, along with the lens, focuses light onto the retina for clear vision.
Hyperopia (also called Farsightedness): The condition in which your cornea is too flat, your eyeball itself is too short or your lens is too narrow. Hyperopia focuses light rays behind your retina and results in the inability to focus clearly on close objects.
Lens: Biconvex and transparent, your crystalline lens is located behind the cornea and works in conjunction with the cornea to focus light onto the retina for clear vision.
Myopia (also called Nearsightedness): The refractive condition in which your cornea is too steep, your eyeball is too long or your lens is too wide. Myopia causes the light rays to focus in front of your retina, which in turn results in the inability to see objects in the distance.
Presbyopia (literally ‘old eye’): The lens of your eye becomes rigid, loses its flexibility and thus its ability to focus on near objects. Presbyopia usually begins its onset around age 40.
Our recommendation: Acuvue Oaysys for Presbyopia. You’ll notice a balanced light spectrum across many planes of vision –near, far and in-between. These bi-weekly disposables are perfect for those who struggle with low light activities.
Refraction: In an eye examination, refraction determines your need for corrective lenses based on your eyes’ ability to refract light/form an image on your retina.
Retina: The multi-layered, light-sensitive tissue that lines the back of the eye. The retina captures light images from the cornea and lens, converts them into electrical signals and sends them – by means of the optic nerve – to your brain.
Visual Acuity: Simply, this is your vision’s clarity. For instance, normal visual acuity is the considered to be 20/20 on the Snellen eye chart.
Axis: Indicates the location, in degrees, your astigmatism’s irregularity and works in unison with the cylinder measurement.
Add: The visual correction for bifocal or multifocal contact lenses. Essentially, it is the strength of the lenses you require to read.
Base Curve (BC): The curvature of the inside of the contact lens that allows it to fit comfortably and correctly on your cornea.
Cylinder (Cyl.): This is the correction needed for your astigmatism and is measured in diopters. A minus sign indicates nearsightedness (myopic astigmatism) and a plus sign indicates farsightedness (hyperopic astigmatism).
Diameter: The measure of the lens’s size (it may or may not be on your prescription).
Diopters: Simply, the measure of your lens power.
O.D. (Oculus Dexter): Latin for ’right eye.’
O.S. (Oculus Sinister): Latin for ’left eye.’
O.U. (Oculus Uterque): Latin for ’each eye’. In a prescription, this typically indicates both eyes.
Power: The power is the correction needed for your lenses/prescription and is measured in diopters. It begins with a plus sign referring to hyperopia (farsightedness), then a minus sign referring to myopia (nearsightedness).
Your Contact Lenses
Daily Disposable Lenses: Contact lenses intended for single, one day use only. No cleaning is required as the lenses are disposed of after just one wear.
Our recommendation: Acuvue 1 Day Moist. Convenient, comfortable and ideal for all day wear. Equipped with Johnson & Johnson’s exclusive Laceron technology, these lenses keep your eyes moist, allow them to breathe easily and protect from harmful UV rays.
Daily Wear Lenses: Lenses worn daily, then cleaned and disinfected each evening. These lenses can be used for one week or one month before disposal – follow the time frame given on your prescription.
Disposable Contact Lenses: Standard contact lenses that may be worn on consecutive days, from time to time, for a single day or an entire month.
Extended Wear Lenses: Contact lenses that can be worn through the night/day, for more than one day at a time. They should be removed, cleaned and disinfected at least once a week.
Our recommendation: Air Optix Night & Day Aqua. Designed for continuous wear – up to 30 days straight without removal – these lenses are the first extended wear lenses approved by the FDA. The intricate silicone hydrogel construction allows six times more oxygen to reach the eye than a standard disposable contact lens.
Gas Permeable (GP, RGP or oxygen-permeable) lenses: More rigid, waterless, plastic lenses often prescribed for astigmatism and presbyopia.
Hybrid lenses: Lenses designed with a rigid gas permeable plastic and a soft hydrogel area for clearer vision and greater comfort.
Hard lenses: Rarely prescribed today, these lenses are PMMA and do not allow transmission of oxygen to the eye.
Multi-focal lenses: Lenses designed specifically for those who need help focusing and navigating from one depth of field to the other – for instance, from looking down at a book in your lap to looking up at a television in the distance. Most commonly worn by those with presbyopia.
Our recommendation: Proclear Multifocal. The Balanced Progressive design delivers all day comfort and unbeatable hydration from the time you put them in until you take them out, but most importantly, you’ll notice an easy transition from near to far and everywhere in between.
Soft lenses: Hydrogel (gel-like plastic containing water) lenses which cover the cornea and allow transmission of oxygen to the eye. Silicone hydrogel lenses are the most commonly used lenses today.
Our recommendation: Acuvue Oasys. Designed with Acuvue’s signature Hydraclear technology, these two week disposable lenses stay moist throughout the day and allow 98% of oxygen to pass through to your eyes. Ideal for those who suffer dry eyes from working in front of a computer, or spend most time in AC/heated rooms.
Toric lenses: Lenses designed cylindrically – not spherically, like a standard lens – and prescribed to correct astigmatism.
Our recommendation: Biofinity Toric. These monthly disposable lenses not only manage astigmatism, they’re also FDA-approved for 6 continuous days of extended wear. And on top of that, they’re designed using CooperVision’s Aquaform technology for the most comfortable, hydrated fit.