By focusing a circle of light on the cornea and measuring its reflection, it is possible to determine the exact curvature of the cornea's surface.
通过将一束圆形光圈聚焦在角膜上，测量反射过来的光线，就能得出角膜表面曲率的确切数据。
2
The large curvature of the Earth appearing in the visor reflection is not the true curvature of our spherical Earth, but rather an artifact of the curve of the space helmet.