eye observation

• 目测

eye observation的用法和样例：

例句

1. They estimated the distance by the eye.
   他们目测估计距离。
2. The names of the various lunar formations and lunar landscapes mostly date back to the early history of visual lunar observation.
   各种月面结构物和地形的名称，大都起源于月球目测观测史的早期。