the lensometer by a dispensing optician or a lab optician includes verifying back or front vertex power, orientating uncut lenses for finishing and glazing, and confirming the mounting of lenses into the frame. manual lensmeters can also be outfitted with an attachment to read the back vertex power of a contact lens for modification and verification purposes. the optician uses the refracted, or bent light, displayed within a lensmeter to interpret the sphere, cylinder, and add powers (if prescribed), axis orientation, prismatic effect, and locate the major reference point of the lens. correct interpretation of these readings is critical to the performance of the eyewear and user satisfaction. automated lensmeter an automated lensmeter uses the reflected wavelength of green light off of the lens surface along every lens meridian in order to determine all of the data points that the optician interprets with the manual lensometer. the benefits of an automated lensmeter are increased speed, adjustments for variables in the index of refraction in the lens material, the ability to measure uv and light transmittance, and a decrease in training time while on the job. the drawbacks of automated lensmeters in comparison to manual lensmeters are greater difficulty identifying higher prismatic errors, aberrations, and surfacing power errors (optic waves), and the necessity of the optician not to tip the lens to avoid an erroneous result. corneal reflex pupilometer a corneal reflex pupilometer is a digital device used to measure interpupillary distance (ipd), otherwise known as pupillary distance (pd). the measurement is used to align the major reference point (mrp) of the lenses along the visual axis to reduce unwanted prismatic effect, eyestrain, and lens aberrations. a pd can be taken binocularly (from the corneal reflex of one pupil to the corneal reflex of the other) or monocularly (from the center of the spectacle bridge to the center of the corneal reflex of each eye independently with the non-measured eye being occluded). by providing a rest point on the bridge similar to an eyeglass frame, pupilometers provided a proper reference point for obtaining an accurate monocular pd value. pds are also taken in relation to focus point. the eyes can be focused at infinity (distance), focused near (approximately 16 inches or 40 centimeters), or intermediate (a working distance in between near and distance. because a pupilometer can be dialed to a specific distance and easily occluded, it is often easier to work with. this does not mean that it is more accurate than a skilled optician with a corneal reflex light, a millimeter ruler called a pd stick, and fully adjusted eyewear for certain age groups and pathologies. while a ruler alone is susceptible to parallax error, when it is used in conjunction with the other tools previously mentioned the accuracy can exceed the pupilometer for these certain patient groups the fitting and dispensing of contact lenses requires the use of additional equipment, all with very specific purposes. a keratometer is a diagnostic instrument for measuring the curvature of the anterior surface of the cornea, particularly for assessing the extent and axis of astigmatism. it was invented by the french ophthalmologist samuel hankins in 1880. opticians, like ophthalmologists and optometrists, also use a slit-lamp/bio-microscope to examine the anterior segment, or frontal structures and posterior segment, of the human eye, which includes the eyelid, sclera, conjunctiva, iris, natural crystalline lens, and cornea. the binocular slit-lamp examination provides stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. while a patient is seated in the examination chair, he rests his chin and forehead on a support to steady the head. using the biomicroscope, the optician then proceeds to examine the patient's eye. a fine strip of paper, stained with fluorescein, a fluorescent dye, may be touched to the side of the eye; this stains the tear film on the surface of the eye to aid examination. the dye is naturally rinsed out of the eye by tears. adults need no special preparation for the test; however children may need some preparation, depending on age, previous experiences, and level of trust. the list of equipment used by an optician is extensive and is often specified in jurisdiction specific professional standards of practice. the standards of the college of opticians of british columbia serve as an example. by country canada all provinces in canada require opticians to complete formal training and education in opticianry and then must pass competency examinations prior to receiving governmental licensure. some provinces (ontario and quebec) require a single optician's license that includes both the dispensing of eyeglasses and contact lenses, while the other provinces have two separate licenses, one each for eyeglasses and contact lens dispensing. recent changes to the british columbia opticians regulations allow qualified opticians in that province to test a person's vision and prepare an assessment of the corrective lenses required for a client. using the results of the assessment an optician is able to prepare and dispense eyeglasses or contact lenses. opticians in alberta and ontario are also permitted, under certain conditions, to refract and prepare and dispense eyeglasses and contact lenses. provincial regulatory organizations each canadian province has its own regulatory college or board that provides registration or licensure to its opticians. the regulatory body (often known as a ‘college’ but separate from, and not to be confused with, an educational institute) has a government mandate to protect the public. this includes enforcement of provincial statutes (opticians act) and public awareness campaigns. the national association of canadian opticianry regulators (nacor) the national association of canadian opticianry regulators (nacor) is an organization of all the provincial opticianry regulatory bodies in canada (except quebec). nacor also administers canada's national opticianry examination(s). since 2001, all jurisdictions (except quebec) have agreed to and signed, the mutual recognition agreement among opticianry regulators that ensures labour mobility to all opticians across the entire nation without need for further examination. all provinces (with the exception of quebec) require individuals to achieve a passing mark in a national examination as a requirement of licensure as an optician. despite the non participation of quebec in national initiatives, canadian opticians who relocate to quebec are able to register and practice in that province provided they meet certain language requirements. provincial associations most canadian provinces have their own provincial opticianry associations that look after the interests of their members at the provincial level, such as advocacy. some provincial regulatory agencies have a dual role or purpose and also serve as the association for that province. in addition to protecting their member's interests, provincial associations also undertake public interest initiatives such as providing vision screening for children in schools, or organizing professional development seminars. established in 1989, the opticians association of canada is a national organization of all provincial opticianry associations in canada. the role of the oac is to advocate for the various interests of opticians on a national basis. education as a prerequisite for registration in any province of canada opticians are required to complete a course at one of the nacor accredited teaching institutions. persons from an international jurisdiction may apply to a provincial regulatory agency for an assessment of equivalency of their education. such applications are not unreasonably denied. nigeria dispensing opticians are regulated by optometrist and dispensing optician registration board of nigeria (odorbn). the training programme is a 3-year diploma programme in a board license institution which are located in all geopolitical zones of the nation. some of the training institution are kwara state college of health technology (offa), federal polytechnic (nekede), millenium college of health technology. united kingdom opticians or dispensing opticians are regulated by the general optical council (goc). a dispensing optician advises on, fits and supplies the most appropriate spectacles after taking account of each patient's visual, lifestyle and vocational needs. dispensing opticians also play an important role in fitting contact lenses and advising and dispensing low vision aids to those who are partially sighted and in advising on and dispensing to children where appropriate. the association of british dispensing opticians (abdo) is the qualifying body for dispensing opticians in the united kingdom (uk). the fellow of british dispensing opticians (fbdo) is the base qualification for uk dispensing opticians. this qualification has been awarded level 6 status (equivalent to bsc) by ofqual welsh assembly government and council for curriculum examinations and assessment (ccea). additional qualifications, contact lenses and low vision have been assessed at level 7 (equivalent to an msc). united states in the united states, an optician, through testing, may be certified by the american board of opticianry (abo) to fill the prescription ordered by an ophthalmologist or optometrist. note: the abo exam is not nationally recognized and does not indicate a license to practice as an optician. in roughly half the states, licensing is not a requirement to make or dispense eyewear. many eye doctors do their own dispensing, and it is frequent for eye clinics to have an optician on their premises; or, conversely, for large optical chains to have optometrists in offices on their premises. some opticians learn their skills through formal training programs. professional technical schools and two-year colleges offer programs in opticianry. two-year programs usually grant an associate degree. one-year programs offer a certificate. training usually includes courses in optical math, optical physics, and tools and equipment use. other opticians can apprentice to learn the required skills. many formal education programs will accept hours worked as an apprentice to supplement or replace course credits, as well. united states organizations that impact opticianry on a national level association website opticians association of america http://www.oaa.org/ the commission on opticianry accreditation http://www.coaccreditation.com/ american board of opticianry http://www.abo-ncle.org/ national contact lens examiners http://www.abo-ncle.org/ contact lens society of america http://www.clsa.info/ national federation of opticianry schools http://www.nfos.org/ american society of ocularists https://www.ocularist.org/ the vision council http://www.thevisioncouncil.org/ notable opticians euclid of alexandria roger bacon christiaan huygens isaac newton rené descartes benedictus spinoza james ayscough carl laubman john jacob bausch henry lomb eugene kalt achim leistner anthony mark