Ophthalmic Optics Exam 2 Chapter Questions With Correct Answers

Ophthalmic Optics Exam 2 Chapter Questions With
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Correct Answers
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True //or //false? //When //taking //PD //measurements,

the //person //measuring //covers //or //closes //one //of //his

eyes //at //a //time. //He //never //covers //one //of //his //subject's

eyes. //- //CORRECT //ANSWERS(S)✔✔False



When //is //it //especially //important //to //use //monocular

PD //measurements? //(There //may //be //more //than //one

correct //response.)

// a. //When //eyes //are //asymmetrically //placed.

b. //When //the //prescription //lenses //are //of //high

power.

// c. //When //the //lenses //are //aspheric.

d. //When //the //two //lenses //are //considerably //different

in //power //from //one //another.

//e. //When //progressive //addition //lenses //are //used. //- //CORRECT //ANSWERS(S)✔✔All //of //the
//above




For //bifocal //lenses //with //a //high //plus //correction, //the

near //PD //should //be:

// a. //increased //slightly //over //the //measured //value.

b. //decreased //slightly //over //the //measured //value.

,//c. //left //the //same //as //the //measured //value. //- //CORRECT //ANSWERS(S)✔✔b. //decreased
//slightly //over //the //measured //value.




True //or //false? //The //Essilor //pupillometer //measures

the //PD //using //a //corneal //refl //ex //- //CORRECT //ANSWERS(S)✔✔True



True //or //false? //Because //of //optical //considerations, //it

is //always //best //to //decenter //bifocal //segments

asymmetrically //if //there //are //high //amounts //of

difference //in //the //measured //monocular //PD

positions. //This //is //true //even //if //the //cosmetic //result

of //the //oddly-placed //segment //appears //to //be

somewhat //unusual. //- //CORRECT //ANSWERS(S)✔✔False



To //measure //monocular //PDs //using //the //glazed

lenses //in //the //frame //and //an //overhead //transparency

pen:

a. //the //dispenser //should //mark //the //glazed //lenses //on
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the //horizontal //midline, //directly //below //the //pupil

center.

b. //the //wearer //should //look //at //the //bridge //of //the

dispenser's //nose. //The //dispenser //should //view

the //wearer's //right //eye //with //his //or //her //left //eye

and //the //wearer's //left //eye //with //his //or //her //right

eye.

c. //the //dispenser //should //spot //the //glazed //lenses //at
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,the //center //of //the //wearer's //pupils. //The //wearer

can //view //either //the //bridge //of //the //dispenser's

nose //or //a //distant //object, //as //long //as //the //gaze //is

held //fixed.

d. //the //dispenser //should //spot //the //glazed //lenses //at

the //center //of //the //wearer's //pupils. //The //distance

between //the //marked //dots //is //measured. //This

distance //divided //by //2 //will //yield //the //right //and

left //monocular //PDs.

e. //There //is //a //flaw //in //every //one //of //the //above
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answers. //None //of //them //are //true. //- //CORRECT //ANSWERS(S)✔✔e. //There //is //a //flaw //in //every
//one //of //the //above



answers. //None //of //them //are //true.



May //the //limbal //edge //be //used //as //a //reference //point

in //taking //monocular //PDs? //- //CORRECT //ANSWERS(S)✔✔No



The //distance //PD //measures //out //to //be //64 //mm, //and

the //near //PD //calculates //out //at //59 //mm. //What //is //the

seg //inset //per //lens? //- //CORRECT //ANSWERS(S)✔✔(64-59)/2

(5/2)

2.5 //mm //per //lens



A //person //has //a //prescription //that //calls //for //a //+4.00

add //power. //For //what //distance //would //you //measure

the //near //PD?

, a. //40 //cm
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b. //30 //cm

c. //25 //cm
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d. //20 //cm

e. //arm's //length //- //CORRECT //ANSWERS(S)✔✔c. //25 //cm
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A //prescription //reads:

OD: //+1.00 //sph
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OS: //+1.00 //sph
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+5.00 //add
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According //to //Gerstman's //three-quarter //rule, //how
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much //must //each //lens //be //decentered? //- //CORRECT //ANSWERS(S)✔✔(5.00)*0.75

3.75 //mm //per //lens



Near //PD //can //either //be //measured //or //calculated.

When //measured, //the //distance //from //the //dispenser's

eye //to //the //subject's //eye //should //be:

a. //the //proposed //working //distance.
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b. //the //near //point //of //accommodation.

c. //40 //cm.
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d. //33 //cm.

e. //arm's //length. //- //CORRECT //ANSWERS(S)✔✔a. //the //proposed //working //distance
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A //person //has //a //distance //PD //of //66, //a //low //distance

prescription, //and //a //bifocal //add //that //requires //the

reading //material //be //held //at //25 //cm. //Rounded //to //the