当然还有很多问题需要解决，例如，怎样避免前端透镜的模糊和冻结？

Of course, there were a lot of problems that were necessary to solve. For example, how to deal with misting or freezing of a front lens?

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光线在确定合适角度以后，经透镜底部较薄处折射后从透镜前端发出。

Light enters at the thinner, bottom end of the lens and bounces around until reaching the desired Angle and emerging from the front of the lens.

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