EYE HEALTH
EYE HEALTH GLOSSARY
Acetate
A material commonly used for eyeglass frames because it’s durable, hypoallergenic, and works well with colours.
Addition/Add
This refers to the prescribed magnifying power found on the lower portion of multifocal lenses.
Amblyopia
Commonly referred to as a “lazy eye”. It occurs when both eyes are not working together and the brain is unable to properly merge the two images into one.
Over time, the brain will begin to disregard the weaker eye and rely mostly on the stronger eye. This can cause the eye to begin drifting in the opposite direction from the stronger eye.
This condition typically occurs at a young age and can be corrected with the right pair of glasses. As the individual gets older it makes it much harder to correct the “lazy eye”
Anti-Fatigue Lenses
A single vision lens design with a slight change in correction in the lower portion to relieve eye strain caused by reading or close up work.
Anti-Reflection
A lens coating that eliminating glare on the surface of the lens for better aesthetics and clarity. Also referred to as “anti-glare coating”.
Arm
A component to eyeglass frames that runs along the side of your head and holds your glasses in place. Also referred to as “temples”.
Astigmatism
A common eye condition where the eye has difficulty focusing regardless of distance. This is caused by a slightly irregular shape of the eye. When the eye is shaped more like a football shape instead of a sphere, it prevents light from focusing properly on the back of the eye. This causes blurriness in vision. Learn More
Axis
A section of an eyeglass prescription that is closely associated with the cylinder value. The axis value can range between 1-180 degrees. It represents the direction the lens must be rotated to correct for astigmatism.
Base Curve
The base curve refers to the curvature of the front side of the lens. This term is also used for contact lenses.
Bifocal
A multifocal lens design with two focal zones (distance and reading). This lens has a hard line on the front to separate each zone. View simulation
Blue Light
A high wavelength of visible light that penetrates deep into the eye. Blue light can be found on electronic devices such as computers, laptops, smartphones as well as daylight emitted by the sun.
Bridge
A component of eyeglasses that consists of a small area that sits on the bridge of the nose. Bridge sizes can vary in eyeglasses and affects the overall fit of the glasses.
Contact Lens
A thin, plastic lens that rests directly on the eye to correct vision deficiencies.
Cornea
A transparent layer that forms the front of the eye.
Cylinder
A section of an eyeglass prescription that indicates the strength required to correct astigmatism.
Diabetes
A disease that can cause elevated blood sugar levels that may lead to damaged retinal blood vessels. Damaged retinal blood vessels cause eventual harm to the macula.
Drill Mount
An eyeglass frame design where there is no frame to hold the lenses. A small hole is drilled on each of the lenses (towards the ear) to attach the lenses directly to the temple.
Farsightedness
See “Hyperopia”.
Glaucoma
An eye disease that raises the intraocular pressure of the eye causing damage to the optic nerve. Peripheral vision begins to deteriorate as the pressure in the eye continues to harm the optic nerve.
High Index
A plastic lens types that are thinner and have a higher index of refraction compared to conventional lenses. These lenses are optimal for higher prescriptions for better optics and aesthetics. View simulation
Hyperopia
A common refractive error where objects at a distance can be seen clearly but objects up close are blurry. Often referred to as “farsightedness”. Learn more
Iris
A flat, coloured, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the center. The iris is the portion of the eye where an individual's eye colour can be seen.
Lazy Eye
See “Amblyopia”.
Metal Frames
Eyeglass frames made from metal materials like stainless steel.
Multifocal
A prescribed correction for two or more fields of vision (distance, intermediate and/or reading). View lens options
Myopia
A common eye condition where objects are clear up close but objects become blurry from farther away. It’s caused when the eye has an irregular shape that refracts light rays incorrectly. Often referred to as “nearsightedness". Learn more
Nearsightedness
See “Myopia”.
Nosepad
A small pad-like component on eyeglasses that rests directly on the nose bridge of the wearer. It provides added comfort when wearing eyeglasses and can be made from different materials like metal, plastic, and silicone.
OCT Scan
An abbreviated term for Optical Coherence Tomography (OCT) Scan. It’s the latest innovation for assessing the internal structures of the eye. This revolutionary technology allows our optometrists to take pictures of the back of the eye giving precise data on the health of your eyes.
Office Lenses
Prescription lenses specifically geared for intermediate and/or reading distances. These distance zones are predominantly used in the office or workplace, hence the name “office lenses”.
These lenses are great for working with computers, laptops, smartphones, tablets, and reading. They are available in single vision and multifocal options. View simulator
Ophthalmologist
A medical doctor that specializes in diagnosing and treating eye diseases. They can also conduct eye surgeries, eye exams and prescribe medication.
Optic Nerve
Connects the eye to the brain. The optic nerve carries information from the retina to the brain. It dispatches this information and the brain interprets them into images.
Optician
An Eye Care Professional with formal training and certification to assist the patient in interpreting the eyeglass prescription, and frame fit.
They do not conduct the eye exam themselves but they are responsible for dispensing the glasses to the patient after they are made.
They can also assist in troubleshooting any issues with prescription glasses and can adjust the frames for a better fit.
Optometrist
A doctor that specializes in the field of optometry. They can conduct eye exams, diagnose eye diseases, and prescribe some medication. Meet our optometrists
O.D.
The abbreviated term for “oculus dexter”; Latin for right eye.
O.S.
The abbreviated term for “oculus sinister”; Latin for left eye.
Peripheral Vision
Often referred to as “side vision”. What the eyes can see from the side when the eyes are looking straight ahead.
Photochromic
A light adaptive lens that changes colour when exposed to UV light. The lens will remain clear indoors and darken outside. View simulation
Plano
Refers to a lens with no prescribed sphere power or “0.00”
Polarized Lenses
Eliminates horizontal glare from light reflected onto surfaces. The lens contains a polarizing film that blocks the horizontal light from passing through the lens. View simulation
Polycarbonate
A lens material that is impact resistant and does not shatter. This material is used for prescription safety glasses and sports goggles. View simulation
Presbyopia
The loss of elasticity in the lens of the eye causing farsightedness. This condition is typically associated with the natural process of ageing. View lens options
Prism
A section of an eyeglass prescription that represents the prismatic power needed to correct eye alignment issues.
Progressive Lenses
A versatile multifocal design that blends three focal zones (distance, intermediate, and reading) into one lens. There is a progression of prescribed power from one zone to the next to provide a comfortable viewing experience for the wearer.
Also referred to as “no-line bifocals” because it is a multifocal lens design with no lines visible on the lens. View simulation
Pupil
A dark circular opening in the middle of the iris that dilates and contracts to regulate the amount of light entering the eye.
Pupillary Distance
Refers to the distance from the right eye to your left eye, measured in millimetres. The measurement is based on where your right pupil is relative to your left pupil, hence the name.
Rimless
Eyeglass frames with a metal or acetate material on the top and nothing on the bottom. The lenses are held by a wire, typically nylon, and appear almost invisible.
Single Vision
A prescribed correction for one field of vision typically distance or reading.
Slit lamp
A medical instrument that consists of a high-intensity light source that can be focused into a thin sheet of light onto the eye. It is used in a routine eye exam to assess the internal structures of the eye.
Sphere power
A section of an eyeglass prescription that indicates the strength required to correct vision deficiencies caused by myopia and hyperopia.
Temple
See "Arm"
Titanium
A durable, lightweight metal that is used to manufacture eyeglass frames. Titanium is an excellent material for glasses because it has a high strength-to-weight ratio and does not rust.
Transitions
See "Photochromic".
Trifocal
A multifocal lens design with three focal zones (distance, intermediate and reading) with a hard line on the front of the lens.