Key Words

Question 1

Transparent

Answer 1

of a material or article) allowing light to pass through so that objects behind can be distinctly seen.

Question 2

Translucent

Answer 2

of a substance) allowing light, but not detailed shapes, to pass through; semi-transparent.

Question 3

Opaque

Answer 3

not able to be seen through; not transparent.

Question 4

Reflection

Answer 4

the throwing back by a body or surface of light, heat, or sound without absorbing it.

Question 5

Refraction

Answer 5

the fact or phenomenon of light, radio waves, etc. being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.

Question 6

Lens

Answer 6

a piece of glass or other transparent material with curved sides for concentrating or dispersing light rays, used singly (as in a magnifying glass) or with other lenses (as in a telescope).

Question 7

Iris

Answer 7

flat, coloured, ring-shaped membrane behind the cornea of the eye, with an adjustable circular opening (pupil) in the centre.

Question 8

Cornea

Answer 8

the transparent layer forming the front of the eye.

Question 9

Retina

Answer 9

a layer at the back of the eyeball that contains cells sensitive to light, which trigger nerve impulses that pass via the optic nerve to the brain, where a visual image is formed.