The front hemisphere of the eye contains the lens, cilliary body, and suspensory ligaments. Posterior hemisphere of eye: retina, choroid, tapetum lucidum & sclera Cats are famously known for the way their eyes shine eerily in the dark they, too, have a tapetum lucidum layer which helps them detect prey even on the darkest of nights. The bluish, glittering tapetum lucidum (not present in the human eye) reflects light on to the retina and helps with night vision as it can reflect light even at very low intensities. Its dark colour absorbs light so that it is not reflected around the eye. The choroid contains an extensive network of blood vessels to support the retina. It has layers of photoreceptor cells that detect the colour and intensity of the light that hits them. The retina is a thin layer of tissue that is responsible for converting light into neural signals for visual recognition by the brain. Now that you have separated the two hemispheres, you can easily identify the iridescent tapetum lucidum, the dark choroid, and the transparent retina which line the posterior of the eye – with forceps, try peeling away these layers for closer observation. Along with the aqueous humour (found behind the cornea) it helps maintain the shape of the eye.

You also feel a strange fluid oozing out of the incision and trickling between your fingers this is the vitreous humour. Using a mounting needle, create a small puncture in the sclera midway between the cornea and the optic nerve – with the puncture as a starting point, you can now use the dissecting scissors to cut the eye into two hemispheres.Īs you do so, you notice just how tough the sclera is. Place the eye in a dissection pan and rotate it so that the cornea is pointing to the left and the optic nerve is on your right. Turning the eye reveals the extrinsic muscle bundles (a human eye would have 6, however, since you are dissecting a sheep eye, you can only see 4) and the optic nerve. Observe the front of the eye where the cornea, sclera, and fatty tissue can be identified. The human eye is around 24 mm in diameter and roughly spherical, slightly reminding you of a marble. You pick it up (gingerly since this is your first dissection and you’re accustomed to seeing eyes in the context of a human face) and notice that it is cool to touch, chilling your fingers through the nitrile gloves. Picture this: sitting before you on the lab worktop is an eye which gazes into yours as you stare with fascination. That's the point John was making.The eye has been beautifully and carefully designed for its function this post will explore the anatomy of the eye (accompanied with images from a dissection). Additionally, keeping your kids from other people with opposing viewpoints from your own isn't helping them, it's indoctrination. There's a reason that you need a college degree in education to be a teacher. Most parents do not have the knowledge, skills, or education themselves to be an effective teacher for all subjects. However home-schooling, for most people, isn't the answer. The public education system desperately needs an overhaul. Well educated (and socialized) children grow up to be intelligent adults with empathy and a worldview bigger than their own back yard. They are easier to control, and they make easy red votes.

The less educated are far more likely to fall for the propaganda. The republicans are actively working to destroy education. The fact that public school education is extremely lacking, especially in deep red states, is not an accident or oversight.

Dissecting sheep eye