ARTICLES AND INFORMATION
The eye care industry is constantly changing, and with each year bringing new technological wonders, it’s important to stay informed. Check out our latest articles and be in touch with any questions.
GLOSSARY OF TERMS
ACCOMMODATION
The eye's ability to clearly see objects at close distances.
ADDITION
The optical power (of a lens) required for near vision, in addition to that required for far vision.
AMBLYOPIA
Amblyopia, or lazy eye, is reduced visual acuity that cannot be improved by wearing eyeglasses.
AMD
Age-related macular degeneration, a disease that damages the macula, the central part of the retina, leading to a loss of central vision and leaving only the peripheral or lateral vision intact.
AMETROPIA
Eyesight disorders that prevent a clear image from forming on the retina (myopia, hyperopia, astigmatism).
ASTIGMATISM
An irregularity in the curvature of the cornea, resulting in unequal blur in the two principle meridians.
BIFOCAL LENS
Lens with two points of focus, designed to relieve presbyopia. The lower part of the lens allows near vision; the rest of the lens is designed for far vision.
CATARACT
Opacification of the crystalline lens. An extraction of the lens is usually replaced by an intra-ocular lens (implant).
COATINGS
Applied to corrective lenses after surfacing to be scratch-resistant, anti-reflective, polarizing, color, anti-static, anti-smudge.
CONTACT LENSES
Small soft or rigid lenses floated on the tear film over the cornea to correct eyesight.
CONVERGENCE
Reflex that enables the eyes to focus on a single point in near vision.
CORNEA
Transparent front part of the globe shaped like a slightly domed cap. It is the primary focusing structure with the lens.
CORRECTIVE LENSES
Corrects eyesight disorders and is a combination of material, optical surface and coatings.
CRYSTALLINE LENS
Transparent biconvex lens located behind the pupil; refracts light to focus images on the retina.
DIGITAL SURFACING
Precise surface cutting using single point turning; cutting height is controlled at all points on the lens.
EMMETROPIA
Clear and comfortable eyesight in both far and near vision. Emmetropia is the opposite of ametropia.
FOVEA
Small depression in the central part of the macula located close to the optical axis of the eye.
GLAUCOMA
Increase in intra-ocular pressure resulting, if left untreated, in an irreversible deterioration of the optical nerve and of the retina, as well as an alteration of the visual field, i.e. a reduction in visual performance, often accompanied by headaches and aching eyes.
HALF-EYE LENSES
Lens for near vision only shaped like the lower half of a normal lens.
HYPEROPIA
Far-sightedness, an eye that is too short and/or insufficiently powered. The image forms behind the retina, which explains why the hyperopic subject has better eyesight in far vision than in near vision. In cases of mild hyperopia, the subject sees correctly in near vision by compensating the hyperopia through accommodation. In cases of severe hyperopia, the eye can no longer compensate in this way.
INTRAOCULAR PRESSURE
Fluid pressure exerted inside the eyeball (ocular globe), which keeps the wall taut.
IRIS
Circular membrane that delimits the pupil. The iris acts as a diaphragm that contracts according to the intensity of light.
MACULA
Central part of the retina. Composed uniquely of cone cells and enables precise vision.
MYOPIA
Near-sightedness, an eye that is too powerful or too long. The image forms in front of the retina; a person with myopia thus sees badly in far vision but well in near vision.
OPHTHALMOLOGIST
Physician, surgeon specialized in the treatment of eye diseases, conditions and eyesight correction.
OPTICIAN
Eyecare professional, designs and adapts eye-glasses in accordance with measurements specific to each wearer.
OPTOMETRIST
Eyecare professional, conducts refractive examinations, fits contact lenses and assesses overall eye health.
POLYCARBONATE
Lens material characterized by lightness, impact resistance, high refractive index, UV absorption.
PRESBYOPIA
Eyesight disorder caused by the ageing of the crystalline lens, which with time thickens and loses its suppleness. As the crystalline lens becomes more rigid, it changes shape less easily and the subject sees less and less well in near vision.
PROGRESSIVE LENSES
Corrects presbyopia by varying optical power progressively from an upper to lower part. No lines.
PUPIL
Central opening of the iris through which rays of light enter the eye. The diameter depends on ambient light.
RETINA
Light-sensitive membrane at the back of the eye on which object images are formed and which transmits information to the brain. This hypersensitive membrane plays an essential role in the perception of light, colors, details, shape and movement.
SEMI-FINISHED LENSES
The front surface is finished and the rear face is surfaced on demand.
SINGLE VISION LENSES
Correct ametropia or presbyopia. The power is the same over the entire lens.
STRABISMUS
Eyesight disorder related to a defect in the parallelism of the visual axes. Early detection in children is vital in order to avoid any risk of amblyopia. There are three forms of strabismus.
WHAT CAN YOUR EYES TELL YOU ABOUT YOUR HEALTH?
INSIDE THE EYE
KERATOCONUS
Keratoconus occurs when your cornea—the clear dome (shaped front surface of your eye)—thins and gradually bulges outward into a cone shape losing its round shape. It generally starts affecting people between the ages of 10 and 25. In its early stages it can be corrected with spectacles. As it progresses specialty contact lenses are needed for correction.
ORTHO-K LENSES
Orthokeratology is the use of specially designed and fitted contact lenses to temporarily reshape the cornea to correct myopia ( blurred distance vision). It is sometimes called “braces” for your eyes. The lenses are worn at night to reshape the front surface of the eye while you sleep. The last few decades have seen a steady rise in myopia (blurred distance vision) across the globe. Evidence suggests that behavioral and lifestyle influences including and genetics contribute to the myopia “epidemic”.
DRY EYE DISEASE
According to the TFOS DEWS II Report 2007 (Tear Film and Ocular Surface Society Dry Eye Workshop), dry eye is a multi-functional disease of the ocular surface characterized by a loss of homeostasis of the tear film and accompanied by ocular symptoms in which tear film instability and hyperosmolarity, ocular surface inflammation, damage and neurosensory abnormalities play etiological roles. Some of the factors that may contribute to dry eyes include gender, hormones, age, systemic and topical medications.
GLAUCOMA
Glaucoma is a group of eye conditions that damage the optic nerve which is vital for good vision. This damage is often caused by abnormally high pressure in your eye. It can be monitored by a visual field test. Glaucoma is one of the leading causes of blindness for people over the age of 60.
AGE-RELATED MACULAR DEGENERATION
AMD is a disease that affects a patient’s central vision. This loss can be severe. Risk factors for AMD include being over 50 years old, smoking, having high blood pressure and eating a diet high in saturated fat.
DIABETIC RETINOPATHY
This is the damage to the blood vessels of the retina caused by uncontrolled diabetes. This damage is measured and monitored by retinal photography. Damage to the retina can lead to blindness.