Cornea

<p>Nov 26, 2013 05:44 PM</p>

<p>

wiki says &nbsp;2/3's of eye's optical power

(see Prof. Peter Pinsky lecture below: &nbsp;says &nbsp;80% of refraction of eye

and passes 95% of light!)</p>

<p>

Humans: &nbsp;refrac power is 43 diopters!</p>

<p>

note: &nbsp;kerato is from the Greek for horn (as in keratitis or in stratum corneum)</p>

<p>

no blood vessels in cornea (would interfere with transparency);

nutrients vis diffusion;</p>

<p>

diameter is 11.5 mm and thickness is about 500 to 600 microns in center and 600 to 800 microns at periphery.

immune privilege (immature resident immune cells.

O2 is direclty from the air.</p>

<p>

Corneal stroma: &nbsp;thick transparent middle layer of collagen fibers about 200 layers each about 2 microns thick.</p>

<p>

innervated by ophthalmic division of trigeminal N: &nbsp;one of most sensitive tissues of body.

pain receptors &nbsp;300 to 600X the density of fibers in skin and 20 to 40X that of dental pulp.</p>

<p>

&nbsp;</p>

<p>

&nbsp;</p>

<p>

&nbsp;</p>