What is Eye?

1. vitreous body 2. ora serrata 3. ciliary muscle 4. ciliary zonules 5. canal of Schlemm 6. pupil 7. anterior chamber 8. cornea 9. iris 10. lens cortex 11. lens nucleus 12. ciliary process 13. conjunctiva 14. inferior oblique muscle 15. inferior rectus muscle 16. medial rectus muscle 17. retinal arteries and veins 18. optic disc 19. dura mater 20. central retinal artery 21. central retinal vein 22. optic nerve 23. vorticose vein 24. bulbar sheath 25. macula 26. fovea 27. sclera 28. choroid 29. superior rectus muscle 30. retina.

The eye is the sensory organ located on the front facial region in charge of reacting with light to help provide images to the brain.

Formation and Orientation
The eye’s physical external appearance consists of the cornea, the sclera, the limbus, the iris and the pupil. To enclose these and more, the eye is made up of three coats. The innermost coat of the eye is the retina. The middle layer contains the choroid, ciliary body and iris. The final layer is made up of the cornea and sclera. In these layers, the aqueous humor and vitreous body are liquids and semi-liquids connected by the pupil.
In order to focus, the eye adjusts the iris which changes the size of the pupil to regulate the light taken in. A small area of the retina is called the fovea centralis and in order to get a clear image, the brain centers this area on the object of interest.

Each eye contains the lateral rectus, the medial rectus, the inferior rectus, the superior rectus, the inferior oblique and the superior oblique. These extraocular muscles create different tensions which translate to eye movements.
Saccades and microsaccades refer to the drifting of the eye caused by the brain’s frontal lobe. All while the vestibule-ocular reflex is the focus of the retina on a particular spot when the head moves to retain the image. Similarly, smooth pursuit movement allows for an image to be captured as both the head and eyes move. To combine saccade and smooth muscle movement, the optokinetic reflex moves the eye back to its initial position where it first captured the image.

Function
The eye is the organ that creates a visual representation of the surrounding environment and that is its main function as an organ.
Image Caption: The human eye. Credit: Wikipedia