This document discusses aniseikonia, a condition where the two retinal images differ in size. It notes that anisometropia above 2 diopters can cause symptoms or issues with binocular vision. While anisometropia was thought to be refractive in origin, studies found subjects had axial anisometropia due to differences in vitreous chamber depth. Contact lenses produced less aniseikonia than spectacles, and this is explained as contact lenses providing optical magnification or minification that better matches the retinal receptor sampling in myopic or hyperopic eyes compared to spectacles. The document concludes that naturally occurring anisometropia is typically axial in origin, and contact lenses are better than

3. Retinal Projection

6. Axial Anisometropia

7. Refractive Anisometropia

9. Retinal Image

10. Retinal Image

11. Spatial Distortion: Size Lens

17. Biometry: Corneal Power

18. Biometry: Axial Length

19. Biometry:VCD

20. Ratio of AL:K

21. Aniseikonia: Spectacles

22. Aniseikonia: Contact Lenses

23. Improvement in Aniseikonia

25. Retinal Receptors

26. Retinal Sampling

27. Emmetropia

28. Myopia

29. Myopia

33. Models of Ocular Growth

34. Predicted VA Spectacles and CLs

35. Visual Acuity

36. VA and Rx