The eyelid protects the front part of the eye. The lid helps keep the eye clean and moist by opening and shutting several times a minute. This is called blinking, and it's both a voluntary and involuntary action, meaning you can blink whenever you want to, but it also happens without you even thinking about it. Anderson, RC; Anderson, JH (1999). "Sensory irritation and multiple chemical sensitivity". Toxicology and Industrial Health. 15 (3–4): 339–345. doi: 10.1177/074823379901500308. PMID 10416286. Hyperopia ( farsightedness): You can’t see near objects clearly. It can happen when your eye is “too short” for the lens to focus light the way it should. Distance vision may or may not be blurred too. Lens, 2. Zonule of Zinn or Ciliary zonule, 3. Posterior chamber and 4. Anterior chamber with 5. Aqueous humour flow; 6. Pupil, 7. Corneosclera or Fibrous tunic with 8. Cornea, 9. Trabecular meshwork and Schlemm's canal. 10. Corneal limbus and 11. Sclera; 12. Conjunctiva, 13. Uvea with 14. Iris, 15. Ciliary body (with a: pars plicata and b: pars plana) and 16. Choroid); 17. Ora serrata, 18. Vitreous humor with 19. Hyaloid canal/(old artery), 20. Retina with 21. Macula or macula lutea, 22. Fovea and 23. Optic disc → blind spot; 24. Visual axis (line of sight). 25. Optical axis. 26. Optic nerve with 27. Dural sheath, 28. Tenon's capsule or bulbar sheath, 29. Tendon. Norn, Mogens S. (1974). External eye: methods of examination. Copenhagen: Scriptor. ISBN 978-8787473033.

Your optic nerve is a direct connection between your eyes and brain. How your eyes develop also means your retinas are technically part of your central nervous system, brain and spinal cord.Nakamori, K; Odawara, M; Nakajima, T; Mizutani, T; Tsubota, K (July 1997). "Blinking is controlled primarily by ocular surface conditions". American Journal of Ophthalmology. 124 (1): 24–30. doi: 10.1016/s0002-9394(14)71639-3. PMID 9222228.

Bone, R. A; Landrum, J. T; Dixon, Z; Chen, Y; Llerena, C. M (2000). "Lutein and zeaxanthin in the eyes, serum and diet of human subjects". Experimental Eye Research. 71 (3): 239–245. doi: 10.1006/exer.2000.0870. PMID 10973733. Ophthalmic artery, 33. Artery and central retinal vein → 36. Blood vessels of the retina; Ciliary arteries (34. Short posterior ones, 35. Long posterior ones and 37. Anterior ones), 38. Lacrimal artery, 39. Ophthalmic vein, 40. Vorticose vein.

Cunningham, Emmett T.; Riordan-Eva, Paul (2011-05-17). Vaughan & Asbury's General Ophthalmology (18thed.). New York: McGraw-Hill Medical. ISBN 978-0-07-163420-5. Kjaergaard, SK (2001). Indoor air quality handbook: Chapter 17, the Irritated Eye in the Indoor Environment. New York: McGraw-Hill. ISBN 978-0-07-445549-4. Protect the delicate area around your eyes from damage caused by the sun, squinting and other stressors with Clinique's eye cream. Clinique All About Eyes