1. Refractive Errors. National Eye Institute. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/refractive-errors. Accessed January 30, 2026.
2. Refractive Errors. American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/what-is-refractive-error. Accessed January 30, 2026.
3. Contact Lenses. U.S. Food and Drug Administration. https://www.fda.gov/medical-devices/contact-lenses. Accessed January 30, 2026.
4. Contact Lenses. Centers for Disease Control and Prevention. https://www.cdc.gov/contactlenses/. Accessed January 30, 2026.
5. Vision and Vision Correction. American Optometric Association. https://www.aoa.org/healthy-eyes/vision-and-vision-correction. Accessed January 30, 2026.
6. Glasses and contact lenses. NHS. https://www.nhs.uk/conditions/glasses-and-contact-lenses/. Accessed January 30, 2026.