LENS

Question 1

A device which produces converging
or diverging light rays due to
refraction is known as a

transparent object that bend light

Answer 1

Lens

Question 2

Traditionally, lenses have been made
from glass, but today, they are more
commonly made

Answer 2

Plastic

Question 3

These ophthalmic lenses are used
correct

Answer 3

myopia (nearsightedness),
hyperopia(farsightedness),
astigmatism

Question 4

Also called a converging lens, positive
lenses, pluslenses and condensers.

thicker at the centre than at
the edges

refracts the light rays
so that they come together at a single point

correct hyperopia

Answer 4

CONVEX LENS

Question 5

have two Outward curving edges and are basically
magnifying glasses, and a number of them are
used together in microscopes

Answer 5

Double-convex lenses

Question 6

are flat on one
side and curved outward on the other and get
used in projectors

Answer 6

Plano-convex lenses

Question 7

positive meniscus
are curved in one side and have a more
outward curve on the other. The correct
hyperopia and presbyopia

Answer 7

Concavo-convex lenses

Question 8

Also called a diverging lens

thinner at its center than at
its edges

correct myopia

Answer 8

CONCAVE LENS

Question 9

has curves in one direction
but not the other, causing light to be focused
in a single dimension or axis

correct
astigmatism

Answer 9

CYLINDERICAL LENS

Question 10

offer correction for near and
far vision, but also enable a person to see
clearly at an intermediate level (about the
length of your arm)

correct the intermediate zone

This results in a total of three power
zones, thus the name

Answer 10

TRIFOCAL LENS

Question 11

This type of multifocal lenses has two
prescriptions (one for distance at the top, and
one for near vision at the bottom) with a
visible dividing line or curve on the lens

Answer 11

BIFOCAL LENS

Question 12

contain two or
more lens powers to help you see objects at
all distances after you lose the ability to
naturally change the focus of your eyes due to
age (presbyopia)

Answer 12

Multifocal eyeglass lenses

Question 13

also called a D -seg or straight-top

Answer 13

Flat-top bifocal lens

Question 14

also called the Franklin bifocal

Answer 14

Executive bifocal lens

Question 15

round lens

Answer 15

Round segment bifocal lens

Question 16

small section

Answer 16

D. C Segment

Question 17

lenses are sometimes referred to
as “no-line” multifocals/bifocals because
there is no noticeable line dividing the
different prescriptions thus, they look exactly
the same as single vision lenses.

It eliminates bothersome “image jump”
caused by bifocals & trifocals.

Answer 17

PROGRESSIVE LENS