Don Mutti and Nina Friedman use it to take pictures. Autorefraction has the special property of being very precise. It measures a prescription to within 0.32 diopters, a fraction of a unit of focal power. This shape appears to indicate that the eye was able to grow in all dimensions while staying in proportion. The eye didn t get too long because the crystalline lens inside the eye changed by the right amount.
Myopic children tend to have a prolate shape.
This shape indicates that the eye grew more from front to back than along its equator. This could present two problems related to myopia. Imagine that the growing eye is a balloon you re blowing up while someone else is holding its sides in with his hands. The balloon doesn t get as wide, and it gets longer faster. In fact, it gets longer three times faster than the spherical balloon.