PretectalVision science / Interactive model
The myopia optics lab
Explore the relationship between eye length and focus, then add a correcting lens to see the difference.
THE MYOPIA OPTICS LABTry it live
Illustrative
BaselineMore elongated
Light focuses before the retina. Distance vision blurs.
The idea to take away
In myopia, distant light focuses in front of the retina. Optical correction changes the light path; it does not shorten the eye.
About this model
This is a qualitative optical model. Dimensions, ray angles, and lens shape are illustrative. The eye's focusing power is combined at one plane; the model cannot calculate a prescription or predict eye growth.
What does a correcting lens change in this model?
Go to the source
References checked October 1, 2026Educational reference
Nearsightedness (Myopia)
National Eye Institute
Background on eye shape, refraction, and optical correction.