Surfacing and Benchwork

Question 1

it is how a lens is created

creates the necessary power or prescription

Answer 1

Surfacing

Question 2

a stage when removing material from the surface of the lens

Answer 2

Grinding (surfacing or generating)

Question 3

brings surface of the lens to almost clear

Answer 3

Fining

Question 4

Brings surface of lens to perfect smooth clear finish

Answer 4

Polishing

Question 5

entails the second phase towards completion of an ophthalmic prescription order

Answer 5

Benchwork

Question 6

• it is the operation done, after the lens has been finished from the grinding laboratory
• insertion or mounting the lens to a spectacle frame
• mounting with utmost precision to satisfy the requirements of a given prescription

Answer 6

Benchwork

Question 7

Stages of benchwork in Full Rim frames:

Answer 7

• Centering
• Layout
• Cutting
• Chipping or crumbing
• Edging
• Glazing

Question 8

Stages of benchwork in Semi-rimless/Rimless frame:

Answer 8

• Centering
• Layout
• Cutting
• Chipping or Crumbing
• Edging
• Grooving or Drilling
• Mounting

Question 9

the process of determining and marking the:

• optical center
• axis of a cylinder
• base-apex line of a prism

Answer 9

Centering

Question 10

• this process consists of marking the proper decentration and insetting
• placing the cylinder axis and base apex line in its proper position

Answer 10

Layout (bench)

Question 11

process of tracing the outline of a desired shape former on a lens surface with a cutting implement

Answer 11

Cutting

Question 12

process of removing large or big particles or surplus glass from the lens with the use of pliers

Answer 12

Chipping

Question 13

process of removing small particles of the lens

Answer 13

Crumbing

Question 14

process of removing the excess and irregular glass smoothly from the lens by means of a grindstone

Answer 14

Edge grinding or Edging

Question 15

edging for rimless frame:

Answer 15

Flat edging

Question 16

edging for plastic and metal full rim frame:

Answer 16

Bevel Edging

Question 17

process of boring holes through the surface of the lens indicated for rimless frame

Answer 17

Drilling

Question 18

process of creating a canal in the edge of the lens for semi-rimless frames

Answer 18

Grooving

Question 19

process of inserting a shaped lens of glass into a channeled or grooved eyewire or rim

Answer 19

Glazing

Question 20

process of placing or fitting a shaped lens or glass in a rimless spectacle or eyeglass

Answer 20

Mounting

Question 21

a point on the lens where the line of sight passes

also known as the Visual Point

Answer 21

Wearing Point

Question 22

• the flat or angled surface
• usually the fine ground
• limits the refracting surface of a lens

Answer 22

Edge

Question 23

the frontal outline of the lens

Answer 23

Shape

Question 24

is the difference between the horizontal and vertical diameter of the lens

Answer 24

Pattern of the Lens

Question 25

is the displacement of optical center (O.C) from the wearing point or mechanical center

Answer 25

Decentration

Question 26

purposes of decentration:

Answer 26

• to produce desirable prismatic effect
• to avoid or eliminate undesirable prismatic effect

Question 27

a device used as a guide for cutting the lens in order to obtain the desired shape

Answer 27

Former

Question 28

Kinds of Former:

Answer 28

• Hand former
• Mechanical Former
• Symmetrical formers
• Asymmetrical formers

Question 29

• formers usually made of cardboard
• transparent celluloid or thin sheet metals
• suitable for cutting odd shaped lenses

Answer 29

Hand Former

Question 30

former used for automatic cutting machines

Answer 30

Mechanical former

Question 31

a former having a similar and uniform shape on both temporal and nasal sides

Answer 31

Symmetrical Former

Question 32

former in which the temporal and nasal sides are dissimilar

Answer 32

Asymmetrical Former