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MOD 1 Questions
| Question | Answer |
|---|---|
| a pupilometer is used to measure the | Interpupillary distance |
| Lens calipers are commonly used to measure | lens thickness |
| A Polariscope is used to check inserted lenses for | Strain |
| A lensometer measures the | powers of lenses |
| In the lensometer can't be centered in the central portion of the lensometer target the lens probably contains | prism |
| To physically measure the location of a cylinder the optician would use | A Geneva lens clock |
| if your lens meter reads -.25 with no lens that measure - 3 - 1.50 at 180 is actually | -2.75 - 1.25 at 180 |
| The first step in performing manual lensometery is to | Focus eyepiece |
| Where will the optical center appear in a lensometer when neutralizing a right lens for Base Down prism | above the Target Center |
| The tolerance for lens thickness when specified for special prescription purposes is | 1 millimeter |
| according to ANSI standard basic prescription safety lens shall not be less than | 3 millimeters |
| Materials that best produce polarized light by reflectance are called | dielectric |
| Some characteristics of minus lenses include | Minifies images diverges light Ray images power strengthens as vertex shortens |
| The modern lens material thought to have the most resistance to impact is | Trivex |
| The most commonly used prescription for correcting muscle imbalance in a case of esotropia will be | base out prism |
| the lower the abbe number the | Less the chromatic aberration |
| aspheric lens surface are most commonly used with | High plus lenses |
| Most compound ophthalmic lenses have | both spherical and cylindrical surfaces |
| the optical center of a lens is | A lens location of zero deviation of the optical axis |
| when the optician advises the consumer as to the breakage of lenses the risk of injury should be described in terms of | Impact resistance |
| when using the boxing method to measure A dimensions refers to | the distance across the lens at the widest point |
| OC placement verification is important to ensure | that there is no unwanted Prismatic effect |
| Iseikonic lenses are used for the correction of | Anisekonia |
| Amblyopia is frequently treated with | occluder lenses |
| of the lens materials listed below which one is considered to provide the best Optics | Cr-39 |
| the vertical difference in power between lenses in the following RX is OD: -1 +.50 Ã 045 OS: -1 +.50 Ã 090 | No difference |
| looking to the inside of plus lens creates which type of Prismatic effect | Base in |
| Of the lens materials listed below which has the greatest amount of color dispersion | Cr-39 |
| the correct term used to express the amount of prism in a lens is | prism diopter |
| increasing the diameter of a lens always increases its | Aberrations |
| which formula accurately represents Prentice rule | prism's equal index of refraction times 10 divided by 100 centimeters |
| The dioptric difference between the lenses for the RX of OD + 2 sph OS + .50 sph would be | 1.50 D |
| given the prescription +1.00 +1.00 at 90 how much of the +1.00 cylinder is an effect a axis 90 | 100% |
| What is the power of +2.00 -1.00 at 45 lens in the 90th Meridian | +1.50 |
| of the materials listed below which one does not have built-in UV absorption | Hard resin 1.67 |
| A +3.00 lens has the following Prismatic effect 8 mm below the optical center | 2.4 base up |
| Cr-39 lenses have an index of refraction of | 1.498 |
| the correct term used to express the amount of prism in your lens is | prism diopter |
| If the RX calls for OU +14.00 sph the best lightweight single-vision lenses to use will be | Hard resin 1.67 |
| A lens is ground of using a base curve of Plano and a 10 diopter convex tool the focal length of the lens is | 10 centimeters |
| The refractive index of polycarbonate is | 1.59 |
| plastic lenses are made of a hard resin material known as | Cr-39 |
| 1 prism diopters | deviates a ray of light 1 centimeter at the distance of 1 meter |
| Astigmatism is corrected by a lens having | cylinder power |
| A +3.00 sphere lens has a base curve of +6.00 what is the back surface power | + 3.00 |
| characteristics of a plus cylinder Lance is | It will bring parallel rays of light to a point Focus behind the lens |
| Moving the optical center of a plus lens inward from the corrected PD results in | base in prism |
| If the lenses of a patient wearing -15.00 Spheres are brought closer to his/her eyes what if any effect will this have on the effective power | increase minus power effect |
| and uncut lens must be at least ___ mm in diameter to allow the edging of a 54 millimeters round lens decentered 3 millimeters in | 60 |
| The spherical equivalent of the lens + 1 + 2.50 @ 90 | +3.50 |
| the relationship of front and back curvatures on a spectacle lens will determine | refractive power |
| photochromic lenses will be darkest on which day | cloudy cold day |
| a consumer complains that his old glasses give him better visual Acuity than his new glasses what should the optician do | check the vertex distance and base curve |
| coating lenses by depositing a metallic film such as magnesium fluoride on the surface of a finish lens is done for the following reasons | Reducing reflections |
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dlsems5862