external axis of eyeball

例句：

1. 1.The external axis of the eyeball is crucial for maintaining good vision.
   眼球的外部轴对于保持良好的视力至关重要。
2. 2. During development, the external axis of the eyeball changes to accommodate the growth of the brain.
   在发育过程中，眼球的外部轴会发生变化以适应大脑的生长。
3. 3. A person with an external axis that deviates from the normal can experience difficulty in focusing on distant objects.
   拥有与正常眼球轴偏离的人在聚焦远处物体时可能会遇到困难。