ABO Practice Test with complete solutions

To mount a lens in a nylon suspension type frame, it would be necessary to _______ the lens. a) Drill b) Notch c) Groove d) V-Bevel - Answer- c) Groove The optical center of a lens is: a) At the geometrical center b) One the 180 line c) At the point where the "a" and "b" measurement meet d) A lens location of zero deviation of the optical axis - Answer- d) A lens location of zero deviation of the optical axis The progressive power lens has a progressive zone after where power: a) Gradually increases b) Of the cylindrical increases c) Stays the same d) Abruptly changes - Answer- a) Gradually increases Standard transmissions in sunlenses should range between a) 10% and 30% b) 15% and 30% c) 10% and 25% d) 15% and 25% - Answer- b) 15% and 30% OC placement verification is important to ensure: a) Accuracy of patient pd b) Correct power of the add c) That there is no unwanted prismatic effect d) None of the above - Answer- c) That there is no unwanted prismatic effect Materials that best produce polarized light by reflectance are called: a) Diatomic b) Diametric c) Dielectric d) Diabolical - Answer- c) Dielectric Coating lenses by depositing a metallic film such as magnesium floride on the surface of a finished lens is done for the following reason: a) Reducing light transmitted b) Reducing reflections c) Reducing weight d) Reducing power - Answer- b) Reducing reflections Aspheric lens surfaces are most commonly used with: a) Lenses of low refractive power b) Occluder lenses c) High plus lenses d) Sunglasses - Answer- b) Occluder lenses The most commonly used prescription for correcting muscle imbalance in a case of esotrophia would be: a) Plus sphere b) Minus cylinder c) Base in prism d) Base out prism - Answer- d) Base out prism The use of multifocal lenses is associated with: a) Presbyopia b) Astigmatism c) Phoria d) Tropia - Answer- a) Presbyopia When the optician advies the consumer as to the breakage of lenses, the risk of injury should be described in terms of: a) Impact resistance b) Shatterproff c) Lens inspection d) Lens verification - Answer- a) Impact resisitance When fitting progressive power lenses, certain critical measurements are taken, one of the most important is the: a) Lens size b) Bridge size measurement c) Monocular pupillary measurement d) Temple length measurement - Answer- c) Monocular pupillary measurement When using the boxing method to measure a lens, the "A" dimension refers to: a) The longest diagonal measurement b) The longest up and down measurement c) The distance across the lens at the widest point d) Twice the ED - Answer- c) The distance across the lens at the widest point Some characteristics of minus lenses include: a) Magnifies images, converge light rays images, power weakens as vertex shortens b) Minifies images, diverges light rays images, power strengthens as vertex shortens c) Magnify images, diverges light rays images, power strengthens as vertex shortens d) Minifies images, diverges light rays images, power weakens as vertex shortens - Answer- b) Minifies images, diverges light raysimages, power strengthens as vertex shortens What is the advantage of a short corridor progressive design> a) It allows the use of shallow "B" measurement frames b) It creates asymmetrical design which puts less surface astigmatism in the temporal portion of the lens c) It helps the designer use the maximum amount of asphericity from the top to the bottom of the lens d) They are less expensive to make because the corridor is shorter and therefore requires less production costs - Answer- a) It allows the use of shallow "B" measurement frames Overall temple measurement is most often stated in: a) Millimeters b) Centimeters c) Decimeters d) Meters - Answer- a) Millimeters Iseikonic lenses are used for the correction of: a) Aniseikonia b) Exophoria c) Emmetropia d) Esophoria - Answer- a) Aniseikonia The modern lens material thought to have the most resistance to impact is: a) Aspheric b) Crown glass c) CR-39 d) Trivex - Answer- d) Trivex The type of bridge on a plastic frame designed to rest entirely on nose pads is the: a) Full saddle b) Semi-saddle c) Sculptured d) Keyhole - Answer- d) Keyhole If a person has exposure to sunlight at least 2 hours or more during the day__________________ a) Their tolerance of bright sunlight is increased b) Their tolerance of bright sunlight is decreased c) Their ability to adapt to quick lighting changes is increased d) Their ability to adapt to night vision is compromised if they dont protect their eyes from the sun exposure - Answer- d) Their ability to adapt to night vision is compromised if they dont protect their eyes from the sun exposure Progressive lenses are used to correct for a condtion called: a) Myopia b) Presbyopia c) Anisometropia d) Emmetropia - Answer- b) Presbyopia The lower the ABBE number the _______________ a) Less the chromatic abberation b) More the chromatic abberation c) Thicker then lens d) Thinner the lens - Answer- b) More the chromatic abberation Most compound opthalmic lenses have: a) Both spherical and cylindrical surfaces b) Spherical surfaces only c) Cylindrical surfaces only d) Have a cemented segement for the add power - Answer- a) Both spherical and cylindrical surfaces The instrument that opticians commonly use measure vertex distance is called a (an): a) Ophthalmoscope b) Distometer c) Geneva lens clock d) Lensometer - Answer- b) Distometer To physically measure the location of cylinder, the optician would use: a) Curvature of the cornea b) Refractive power c) Dioptric power d) Intra-occular pressure - Answer- d) Intra-occular pressure The instrument that provides information on the patient's refractive status by reflecting light off the retina is: a) Ophthalmoscope b) Tonometer c) Phoropter d) Retinoscope - Answer- d) Retinoscope The first step in performing manual lensometry is to: a) Focus the eyepiece b) Lubricate the instrument c) Position the eyeglasses d) Position the patient - Answer- c) Position the glasses Which is not a possible solution for the frame sitting too high on the face? a) Strech the bridge (plastic) b) Spread the nose pads c) Bend the guard arms down and re-adjust the vertical pad angle d) Choose a different frame - Answer- c) Bend the guard arms down and re-adjust the vertical pad angle If a patient misses two letters on the 20/30 acuity line, the acuity should be recorded as: a) 20/30-2 b) 20/40 c) 20/40+4 d) 20/30 - Answer- a) 20/30-2 A lensometer measures the: a) Center thickness b) Light transmission c) Power of lenses d) Index of refraction - Answer- c) Power of lenses Where will the optical center appear in a lensometer when neutralizing a right lens for base down prism? a) To the right of the target center b) To the left of the target center