corneal lens lens

clay-bearing and silty clay layer

corneal lens（lenses） lens

Lens-to-lens interval

object lens objective lens

objective lens object lens

plane-concave lens (=plano-concave lens)

plane-convex lens (=plano lens)

short focal length lens (=short-focus lens)

variable focus lens vari-focus lens

vari-focus lens variable focus lens

1 type clay minerals

abandoned clay bricks

abyssal clay

abyssal red clay

acclivous clay wall

Acid Activated Clay

acid clay

acid sprayed clay