凝らす

1. Origins, structure, and basic meaning

• Structure: 凝らす is read こらす.
• Basic usage: It is a transitive verb meaning to focus one's senses or thoughts, or to devote ingenuity and effort.

2. Common pitfalls and similar expressions

• Straining one's eyes
  • 目を凝らす means straining one's eyes in order to see carefully.
• Applying ingenuity
  • 工夫を凝らす means devoting ideas and effort even to the details.