• Aspherical lenses: allows for a flatter lens (the front is flatter than for a spherical glass) and improved optical quality, it is also more aesthetically pleasing.
  • Acetate : cellulose acetate is a derivative of plastic and one of the most used materials in eyewear.
  • Acuity : Visual acuity is the quantity used to measure the ability of the eye. (expressed in diopters)
  • Afocal : the afocal optical system is the zero power . ex . flat glass
  • Adjustment: adjustment of shaping the frame to the wearer's physique . This is a very important step. Indeed, a poorly fitting can affect vision significantly of the client.
  • Amblyopia : functional or organic , it is the progressive loss of visual acuity in one eye that is not used.
  • Ametropia : ametropia is a vision defect that prevents the formation of a clear image on the retina . Myopia , hyperopia and astigmatism are ametropia.
  • Aniseikonia : aniseikonia is the difference in size of retinal images between the right eye and the left eye , which can cause binocular vision and prevent the fusion of two images.
  • Anti glare : Anti glare is an optional configuration of a glass processing, it aims to increase the transmission and therefore the confort of use. It removes up glare from the reflection of light on diopters lens optical system for removing reflections " parasites " and increase the transparency of glass .
  • Astigmatism : Astigmatism is a visual defect usually due to the cornea , whose shape is slightly oval rather than round . Astigmatism can be combined with other v
  • isual defects such as myopia , hyperopia and presbyopia.
  • Astigmatism : the astigmatic has a vague vision of near and far . He does not perceive clearly the contrast between vertical or oblique or horizontal lines .
  • AMD : Macular Degeneration Age-related . It causes the appearance of a central scotoma at all distances.


  • Bridge: Part of the frame that joins the two circles of the telescope lenses .
  • Bevel : Bevel edge glass is cut for mounting the frame


  • Cataract : Cataract is a partial or complete opacification of the lens. Most of the time it is SENILE therefore linked to age. In this case we feel discomfort such as photophobia, opaque veils, and / or a reduction of our visions of far and near .
  • Cornea : The cornea is the small membrane, thin and transparent , which covers the whole front of the eyeballs .


  • Dimension : the dimension is the width of the shape of the caliber of a frame.
  • Daltonism : the Daltonism is an anomaly of genetic origin, which results in a disturbed color perception.
  • Diopter : is flat or spherical surface separating two transparent media of different indices and homogeneous .
  • Data transmission : the fact that you send directly the papers by computer so that the social security reimbursement is faster .
  • Depth of field lenses : are aimed at young people with presbyopia or holders of progressive lenses looking new equipment closely. They provide clear vision near , large and comfortable and also help to see clearly everything that is at an average distance .


  • Emmetropic : the emmetropic eye has no refractive defect
  • Exophoria : Exophoria is the anomaly of the binocular vision characterized by a divergence of the lines when the eyes look at physiological rest .


  • Flex system : flex system , with a small spring, allows branches not deform when her glasses are removed too quickly .
  • Frame pierced : is a frame which branches are directly screwed into the lenses.
  • FOV : Field of vision is the space that the eye is capable of perceiving . In humans, the field of view is approximately 180 °.


  • Glass cutting : Sharp glass is formed with a very thin edge thickness .


  • Hardening treatment : hardening treatment is to apply a coating on plastic lenses to increase their scratch resistance. This protective layer increases the life of lenses.
  • Hydrophobic treatment : treatment for glasses where water slides more easily. Some are naturally hydrophobic materials such as pen and some paper . The hydrophobic treatment enables easier cleaning.
  • Hypoallergenic : the allergenic does not cause allergy ( eg titanium) .
  • Hyperopic : is a person who sees bad closely. His eye is too short for its power or too powerful for its length. This abnormal vision can be corrected by wearing glasses , lenses , or less often surgery or laser.
  • Hyperopia : is due to an insufficiently powerful eye ( "too short" ) . The image is formed behind the retina, which is why the farsighted see better at a distance than up close. In low hyperopia, one sees correctly from far, but at the cost of effort.
  • Hinge : The hinge joint connects the legs to the front of the frame and allowing the withdrawal of branches behind the face . It serves to hold the arms to the face of the bezel . It is thanks to them that the branches bend .
  • Hydrophobic lenses : hydrophobic lenses have a very smooth surface that " leaks " water: the droplets slide and the condensation does not adhere.
  • I

    • Interview lenses : is a depth of field for correcting presbyopia is specially designed for near vision activities glass. It allows you to see up close, and the objects and people around you.
    • M

      • Mineral lenses : is a glass made from sand heated to very high temperatures. It is quite heavy and fragile that breaks very easily , it is very sensitive to scratching. Because of its material is prohibited for children and for people who play sports .
      • Multifocal : Multifocal is the term used to refer to all bifocal , trifocal , any form of mistaken segment ( curved , straight , round )
      • Myopic : the myopic sees far unclear . His eye is too long for its power or too powerful for its length. As hyperopia, this anomaly of vision can be corrected by wearing glasses or contact lenses.
      • Myopia : Myopia is a defect of vision due to a "too long" eye : the distance between the cornea and the retina is too large.
      • The image is formed in front of the retina and the myopic sees unclear from far but very well closely . For the myopic , the distance of clear vision is even shorter than the myopia is high.


      • Ophthalmologist : the ophthalmologist is a doctor who specializes in eye and vision.
      • Optician : they adapt , supply and repair eyeglasses or contact lenses to correct visual defects according to a prescription made by the ophthalmologist . Sometimes he has a degree in optometry , which allows him to make examinations for clients, to evaluate their visual ability .
      • Optometrist : optometrist is qualified to carry out sight tests , measure refractive errors and prescribe glasses if necessary.
      • Orbits : the orbits are bony cavities in which are housed the eyes and protect them.
      • Orthoptist : the orthoptist is the medic helping the rehabilitation of visual disorders for uncoordinated eye movements ( eg strabismus ) .
      • Organic lenses : is a completely created from synthetic materials , mainly CR39 , this material was discovered in the 40s , it has the ability to be lightweight, durable , but it is quite sensitive to scratching this is why many treatments are optional.


      • Pupillary distance : the pupillary distance is the distance between the center of each of your pupils. This distance does not change with time ( except for children during growth ) so if you measured once your pupillary distance , the value will always be used . The semifinals differences pupillary (distance between each pupil and the center of the nose ) is more often used to focus the lens properly , the eyes are not always placed symmetrically .
      • Platelets : the platelet provide a stable support frame on the wearer's nose . Platelets also allow slightly adjust the height of the lens mount.
      • Permanent bearing : is the fact you are wearing a contact lens day and night. Only lenses with high oxygen permeability .
      • Pre-calibration : calibration allows the pre- optimization of the thickness of glass while maintaining the centering and assembly .
      • Presbyopia : is a vision disorder related to age ( sclerosis of the lens, decreasing the effectiveness of accommodative tone ) making it difficult or impossible to focus the vision for reading.
      • Pupilometer : is the unit for measuring pupillary distance .
      • Pantoscopic angle : the pantoscopic angle is the angle that the side of the frame made with the vertical when the frame is placed on the nose of the wearer and that it looks away. Generally , the face of the frame is inclined at about 5 ° to 10 ° with respect to the branches . This angle allows our line of sight to be perpendicular to the plane of the frame. When we walk , we look at the ground about 10m which for a person of 1.80m corresponds to an angle of 10 °.
      • Pupillary height : pupillary height is the height from the bottom of the frame and the center of the pupil. This measurement is used to set the vertical position of the lens in the frame . To be measured , the optician must adjust the glasses on the wearer's nose before measuring the height using a decimeter . This depends on both the morphology of the face of the wearer but also the size and shape of the frame.
      • Photochromic lenses : photochromic lenses contain specific photochromic pigments that darken the glass when exposed to ultraviolet rays from the sun. When ultraviolet radiation weakens the glass becomes clear . This variable tint provides visual comfort .
      • Polarized lenses : polarized lenses are specially designed to protect against glare and reduce unwanted reflections on reflective surfaces , improves contrast and visual perception in case of high brightness ski slope , water surface sea , windshield car.
      • Polycarbonate lenses : has an unparalleled impact resistance . This is the most versatile materials design .
      • Progressive Lenses : Progressive lenses allow both distance vision (upper glass) and near vision ( lower part of the glass) .


      • Rebuilding : is done at the end of installation when the two lenses are mounted . It facilitates adjustment and formats the equipment to make it presentable to the client.
      • Rimless frame : is half encircled and closed by a nylon thread.


      • Sticks : the sticks are the cells of the retina for night vision
      • Strabismus : is a deviation of the visual axes relative to a point of fixation . Concretely convergent strabismus is most common in children .


      • Tint : stop the visible radiation and preserve the glare, but if it is not filtering , it will not stop the invisible UV rays, harmful consequences for the eye .
      • Tenon : Frame element usually located near the hinges branches for closing the circle and holding the glass in place .
      • Thinned treatment : the thinned treatment can reduce up to 40% the thickness and weight of a glass. The tapered glasses are thus more aesthetic and more comfortable for wearers of glasses with sharp correction .


      • Ultra Violet (UV) Ultra Violet are electromagnetic waves located between visible light and X-rays Harmful to skin and eyes .