visual defect的用法和樣例：
例句
- A visual defect characterized by the inability to discern blue and yellow.
藍色盲，第三原色盲具有不能區分黃色和藍色的視覺缺陷 - A visual defect characterized by the inability to see as clearly in bright light as in dim light.
晝盲(症)一種視覺缺陷，其特點是在明亮的光線中和在陰暗的光線里一樣無法看清東西
