Subject: Scientific Videos for all Natural Eyes.
Reference: The is a dynamic system.
Here are two videos to show how this property of all normal eyes are determined. The effect of a negative lens – on the normal eye.
The effect of a positive lens – on the normal eye.
The natural eye is not a frozen box camera – as it is taught in High School.
Based on this objective science – it is possible to suggest that a motivated pilot could convince himself to begin wearing a strong plus (for all near work), and slowly get back to naked-eye 20/20. Pilots have done this – so we know it can be accomplished.
Equally, direct science, confirms the dynamic eye animation you see presented here:
Prevention will always depend on the person himself. It can not be prescribed.