凸レンズ

1. Origins, structure, and basic meaning

• Structure: 凸 denotes a bulging shape; combined with レンズ, it names a lens thicker at the center than at the edges.
• Basic usage: In 凸レンズを通すと、小さな文字が大きく見えた。, small letters appeared larger through a convex lens.

2. Common pitfalls and similar expressions

• Reading the mixed-script term
  • Read 凸レンズ as とつれんず: 凸 is とつ, followed by the loanword written レンズ.