LAB QUIZ 1

Question 1

Hypoallergenic, lightweight frame materials

Answer 1

(lighter than cellulose acetate/zyl) Optyl, Cellulose propionate

Question 2

Frame material w/ memory

Answer 2

(returns to orig molded shape when heated) Optyl

Question 3

Frame material resistant to fading/discoloration

Answer 3

Optyl

Question 4

Impact resistant frame materials

Answer 4

Polycarbonate, Polyamide

Question 5

Datum line/180 line/Fitting line

Answer 5

Horiz line, midway btwn horiz tangents at highest and lowest limits (Along which eye size and bridge size measurements are taken)

Question 6

Boxing system

Answer 6

Draw horiz and vert lines tangent to lens edge on all four sides, forming box around lens

Question 7

A dimension

Answer 7

(Eye size) “Width” distance btwn vert lines (in mm)

Question 8

B dimension

Answer 8

“Height” distance btwn horiz lines (in mm)

Question 9

C dimension

Answer 9

(Eye size under Datum system) Horiz length of lens along Datum line

Question 10

DBL

Answer 10

(Bridge size) Distance btwn lenses, from nasal vert line of OD to nasal vert line of OS

Question 11

DBC

Answer 11

Distance btwn GCs of each lens (= A + DBL)

Question 12

Info req to order frame for patient

Answer 12

Manu, Frame name, Color, Eye size, DBL, Temple length

Question 13

Criteria to ensure proper fit

Answer 13

Bridge size, Bridge flair angle, Temple length/style, Eye size

Question 14

Frame selection for high myope

Answer 14

Small eye size, Round eye shape, Match FPD and IPD (min decentration), Wraparound endpiece

Question 15

Temple flair

Answer 15

Distance btwn two temples as they course back to the ear

Question 16

“Truing” the frame

Answer 16

Pre-adjusting the frame

Question 17

Pre-alignment procedures

Answer 17

1) 4 pt touch (eyewires and crest of temple rest on flat surface, when frame placed upside down), 2) Lenses in same plane (No X-ing, twisting about the bridge), 3) Parallel setback (temple) angles = Positive (more common) > 90 deg @ endpiece, btwn frame front and center line of temple, 4) Slight pantoscopic tilt (lowers OC), 5) Nosepads level, @ same horiz/vertex distance from face, 6) Lenses properly mounted (not loose/tight/pushed out w/ hand P) - Multifocals w/ seg line level on both sides, 7) Eyewire/temple screws properly seated/secured, 8) Proper facial wrap, 9) Proper folding angle

Question 18

Test for temple fit (not too loose)

Answer 18

Forward Draw/Palpation test

Question 19

Fitting triangle

Answer 19

(of pts of contact btwn eyewear and skull) - Crest of bridge, Skull at top of R ear/L ear&raquo_space; Bal - Even weight distrib @ each of 3 pts

Question 20

Frontal angle

Answer 20

(Bridge flair) - How nose angles out from midline (as seen from above)

Question 21

Splay angle

Answer 21

(Transverse angle, larger for flatter bridge) - Btwn line through center of bridge and face of nosepad (as seen from the front)

Question 22

Vertical angle

Answer 22

Angle away from vert, indicated by line down pad’s center (as seen from the side)

Question 23

Eyewire screw vs. Temple screw

Answer 23

Threads all along shaft vs. Threads only at lower part of screw

Question 24

More heat resistant –> Less heat resistant when doing frame adjustment

Answer 24

Nylon, Optyl = Propionate, Zyl

Question 25

Lens glazing - Where

Answer 25

Process of inserting finished lens into frame (Gen in front - Easier to insert, Fall out from front, away from patient’s face, if dislodged w/ impact)

Question 26

Salt pan - Adv and Disadv

Answer 26

(Adv) Less expensive, Easier to pile, Easily dissolved w/ H2O if trapped in eyewire groove, (Disadv) Sticks to frame, Req often replacement, Dirty/lumpy when wet, Heats slower

Question 27

Glass beads - Adv and Disadv

Answer 27

(Adv) Not req often replacement, No clumping when wet, Heat quicker, (Disadv) More expensive, get stuck in eyewire groove

Question 28

Where lens clock readings are the same

Answer 28

Entire principal meridian (w/ same surface P), Along any meridian // to meridian of interest

Question 29

Sig of reticule location

Answer 29

At secondary focal pt of objective, primary focal pt of eyepiece&raquo_space; Position doesn’t change regardless of what lens is against lens stop &raquo_space; // light enters objective, // light emerges from eyepiece

Question 30

Effect of adjusting eyepiece

Answer 30

// light no longer emerges from eyepiece, changing clarity of the target&raquo_space; Small diff in P reading

Question 31

Sig of lens stop location

Answer 31

At secondary focal pt of std lens&raquo_space; Peq (btwn std and unknown lens) always = P std (regardless of unknown lens)&raquo_space; Constant image size

Question 32

Uses of lensometer

Answer 32

Duplication of Rx, Verification of Rx (to det accuracy of fabrication), Neutralization of Rx (to det Rx), Laying out a lens for edging, Conversion of several trial frame lenses to single lens equiv (in back vertex P)

Question 33

% of frames in dispensary that are typically imported

Answer 33

90%