Safety Eyewear Maintenance & Calibration

Question 1

What do we do when the pattern size does not match the eyesize?

Answer 1

set the edger 0.5mm x the difference between eyesize and pattern size

Question 2

What is chamfering? 2

Answer 2

-Process of smoothing the sharp edges of the holes in a lens
-also known as equivalent to safety/pin bevelling.

Question 3

What are the 3 keys points to the basic impact ball drop test?

Answer 3

-Lens must be 3mm thick, or 2.5mm thick if power in the most plus meridian is +3.00D or more
-Must contain manufacturers logo
-Must withstand a 1-inch steel ball dropped from 50 inches

Question 4

What is the test that checks for impact resistance called?

Answer 4

Ball Drop Test

Question 5

What are the 3 keys points to the high impact ball drop test?

Answer 5

-Lens must be a minimum of 2mm thick
-Must contain manufactures logo with a +
-Must withstand a 1-inch steel ball dropped from 50 inches, and a ¼ inch steel ball travelling at 150 feet per second

Question 6

What is the purpose of side shields in safety glasses?

Answer 6

Stops debris coming in from the side of the frame.

Question 7

Define safety glasses.

Answer 7

-Safety approved frames must meet the ANSI Standards which
test for high-velocity impact, and high-mass impact

Question 8

How can you tell a lens has been chemically tempered
(hardened)?

Answer 8

Submerge in glycerin solution while viewing through two crossed polarizing filters

Question 9

How can you tell a lens has been heat tempered
(hardened)?

Answer 9

observe the lens through two crossed polarizing filters

Question 10

Why must we calibrate edgers?

Answer 10

keeps machine working accurately and effeciently

Question 11

What are the 6 steps to checking the edger axis?

Answer 11

1.Clearly mark one lens pair with non-soluble ink.
2.Accurately block both lenses with no decentration.
3.Choose a squared pattern.
4.Flat-edge or rough only.
5.Hold the edged lenses back-to-back.
6.Check to ensure that the marks on the lenses overlap.

Question 12

what are the 4 factors we need to know when talking about edger wheels?

Answer 12

-Grit size
-Diamond Concentration
-Depth of diamond layer
-Type of bond used to hold the diamond to the wheel.

Question 13

What is a glazed wheel?

Answer 13

-a condition that happens to the wheel when there is exposed space between the diamond particles and it fills with ground lens materials

Question 14

During the impact resistance test what must/must not the frames/lenses do? 2

Answer 14

-Frames and lenses cannot break
-Frames and lenses cannot come in contact with the eye

Question 15

When calibrating patterned and patternless edgers what must we remember? 2

Answer 15

-Specific to each type of patterned edger
-consult with technician or refer to manual

Question 16

Review the steps for Blocker Calibration

Question 17

What kind of lens is chosen during blocker calibration?

Answer 17

lens with the flattest available front curve is chosen

Question 18

What two machines are part of the edging process?

Answer 18

Frame Tracer
Patternless Edger

Question 19

What is used to calibrate a patterned edge?

Answer 19

physical guide/temple

Question 20

How do you check accuracy of a patterned/ patternless edger ?

Answer 20

cut test lenses and adjust accoridingly if not correct

Question 21

What is used to calibrate a patternless edge?

Answer 21

digital mapping

Question 22

What is the issues with rimless and semi-rimless eyeglasses?

Answer 22

Lens is exposed so if they are dropped on its edge it can cause microcracks and a stressed and a less impact resistant lens.

Question 23

What is wheel differential?

Answer 23

is the difference in size of a lens after it has been rough edged compared to its final size

Question 24

What is dressing a wheel?

Answer 24

Refers to sharpening and cleaning the gridning surface by removing glazed or clogged layer, restoring the cutting ability