ABO Practice Test Questions and Answers Graded A

ABO Practice Test Questions and Answers Graded A Corpuscular the theory which explains light as a stream of invisible bundles of energy Photons the visible bundles of energy Electromagnetic Theory The theory which explains light as moving in a series of wave pulsations. 186,000 miles per second the speed of light in air ray a point of light pulsating in a straight line all colors the colors that visible or white light are composed of base a prism will bend light towards its one meter one diopter prism will deviate a ray of light one centimeter in a distance of apex the image being viewed through prism will always be displaced towards its refraction the bending of light as it passed from a medium of lesser density to a medium of greater density is known as refractive index the speed of light in air divided by the speed of light in a material optical center the single point on an optical lens through which light may pass without being deviated converging/against motion plus lenses can be characterized by these two attributes diverging/with motion minus lenses can be characterized by these two attributes minus spheres simple myopia or nearsightedness can be corrected with these type of lenses plus spheres simple hyperopia or farsightedness can be corrected with these type of lenses cylinder lenses an eye which requires a different correction in different meridians can be corrected with these type of lenses 530 mm the radius of curvature of a one diopter lens +1.75 The total power of a lens with a +6.00 diopter front surface and a -4.25 diopter back surface lens. two plus surfaces a biconvex lens 1 meter the focal length of a one diopter lens +3.00 +2.00 x 005 the correction transposition of the following rx: +5.00 -2.00 x 095 out the pupillary distance ground too wide for a plus Rx will result with this type of prism base out the pupillary distance ground too narrow for a minus rx will result with this type of prism base base in and base in this combination of prism is not a canceling situation base up and base up this combination of prism is not a compounding situation radius of curvature not an element of the Prentice Rule formula 1.5 diopters the resulting total prismatic effect of a pair of 3 diopter spheres that is 5mm too wide plano the total power of the following rx at an 180 axis: +2.00 -2.00 x 090 +/- 2 degrees the tolerance for a cylinder of 1.62 diopters or greater 2/3 diopters the recommended limit for horizontal prism tint this will not affect lens thickness effective diameter this is twice as long as the given radius of any shape saggital value or sag an indictor of lens thickness closet distance between lenses DBL "A" Box measurement referring to the horizontal straight line between the farthest nasal and the farthest temporal point of a lens reads base curves not a function of the lensometer reticle the concentric circle configuration within the scope of the lensometer front side the bifocal add must be read with this side on the lens against the lens stop binocular the pd measurement which indicated the distance from the center of the pupil to the center of pupil monocular this type of PD best compensates for facial asymmetry upper right You are looking at a right lens in the lensometer. The Rx call for 1 BU and 2 BI. You find the optical center in this quadrant. -7.50 A lens has a front curve of +6.50. What back curve would yield a corrective power of -1.00? -6.50;-7.50 If a lens has a front curve of +4.50 which back curves would be required to create a lens with a power of -2.00 -1.00 x 180? 0.1766m A +3.00 diopter lens has this radius of curvature. violet The component of visible light has the shortest wavelength. apex to apex Minus lenses are though as two prisms or as a series as these. compound hyperopic astigmatism The following rx corrects this type of visual condition. +2.00 -1.50 x 180 OU steeper As plus power increases the base curves selected result in this effect on the lens. 25 cm +4.00 diopter lens has this focal length 1/diopters focal length formula optic nerve Visual images are transmitted to the brain via this pathway. infrared This portion of the electromagnetic spectrum falls just beyond the longest wavelengths of the visible spectrum. monel a non-hypoallergenic frame material 1.586 refractive index of polycarbonate lens width the A measurement in the boxing system calipers unit of measurement for lens thickness retroscopic tilt frame eyewires are closer to the brow than the ceeks The Food & Drug Administration requires impact resistance test for dress eyewear 0.56 ounces the weight of the steel ball used to test glass lenses in the drop ball test for dress eyewear distometer measures vertex distance Prentice's Rule (D*decentration)/10 spherical equivalent formula power times 0.5 prentice's rule used to calculate prismatic effect minifies the characteristic of a minus lens cornea and sclera the limbus is in conjunction with these two slow down when rays of light go from a medium a less density to a more dense medium they do this 450 nm to 495 nm the blue portion of light is between this two on the visible spectrum in exotropia might be corrected with base in this direction BUMM acronym used for remembering in which lens slab off in ground into and what direction the base is BUMM= base up most minus less chromatic aberration the higher the abbe value segment the base curve of a multifocal lens is measured here Jaeger chart used to check near vision aniseikonia unequal image sizes of the two retina wet/dry the two types of macular degeneration trivex the most impact resistance lens apex of the cornea a distometer measure the distance from the back surface of a spectacle lens to vertex compensation formula P squared times the mm moved divided by 1000 at the dot beneath the fitting cross where prism is verified in PALS down direction of the prism in reverse slab off zyl common named used for cellulose acetate hyperopia a shorter eyeball than normal horizontal polarized lenses filter light in this meridian a steeper base curve might cause a patient to say that distant objects look larger +1.50 ou A patient with the following Rx wants a reading only pair, what would the Rx be? -0.50OU +2.00 palpebra eyelids Nu Value the measure of color distortion hypophoria corrected with base up prism weight what specific gravity measures cataracts this type of vision problem may be corrected the IOL keratitis inflammation of the cornea geometric center the point where lines that bisect the horizontal and vertical measurements of the lens in the boxing system intersect cornea provides appx. 43 diopters of power to an eye's refractive system 20 feet the standard for optical infinity converge when a patient's eyes move inward to focus at near antireflection lens treatment that allows the maximum amount of light to pass through the lens diopters unit of measurement for ophthalmic prism on the temporal side of the lens the side of the lens where the add power if etched 34mm the industry standard between the alignment markings on a progressive lens colmascope another name for a polariscope anisometropia differing refractive errors for the two eyes parallel light rays from a point source twenty feet or more away are said to be medial rectus the muscle that moves the eye inward ultraviolet radiation these wavelengths of light are responsible for activating photochromatic lenses ocular dexter or OD the latin term for the right eye ocular sinister the latin term for the left eye irregular the type of corneal astigmatism that does not have meridians that are 90 degrees apart epithelium the outer layer of the cornea prism diopter the unit that is used to measure the displacement of a ray of light concave the red numbers on a lens clock read the curves on a lens saddle bridge the most common bridge type found on most plastic frames accommodation the process where the crystalline lens thickens to allow focusing on near objects cellulose acetate the most commonly used plastic material BU prism a plus lens moved from it's primary positions results in this type of prismatic effect crown glass lens material that filters the least UV radiation fibrous tunic consists of the sclera and the cornea ion exchange the chemical tempering of a glass lens a high myope bothered most by internal reflections amblyopia a child wearing an eye patch is most likely be treat for this condition colmascope or polariscope measures lens stress yellow the best tint for shooting glasses presbyopia most closely associated with the hardening of the crystalline lens the cornea supplies 70-75 % of the eye's focusing power refractive errors myopia, hyperopia and astigmatism decrease pantoscopic tilt to effectively raise the bifocal seg height tonometer measures intraocular pressure The Department of Health and Human Services Government agency charged with enforcing HIPPA HIPPA the Health Insurance Portability and Accountability Act pseudophakia the condition where the crystalline lens has been replaced with an artificial lens antimetropic Rx has opposite signs meniscus the terms for a lens that contains one convex and one concave surface Ishihara test test used to screen for color blindness nickel the material in metal frame most likely to cause allergic reactions peripheral vision and blind spots the visual field tests test for these more minus a minus lens moved further away from the eye has is compensated with Vogel's formula formula used for best base curve selection oleophobic means oil repelling latent hyperope uses accommodation to see clearly at distance iseikonic lenses correct unequal retinal image sizes 4mm temporally A -5.00 lens must be decentered this many mm to induce 2 diopters base in prism specific gravity defined as grams per cubic centimeter Fresnel prisms applied to the back of the lens with the ridged side out hyperopic most children are born myopia most children born hyperopic shirt towards this condition as they grow more minus a minus lens moved further away from the eye has is compensated with 1.49 the refractive index of CR-39 compound myopic astigmatism focal points meet in front of the retina simple hyperopic astigmatism of the two focal points, one hits the retina and one meets behind the retina