Vision Elements of the Eye - Lens and Aqueous Humor

The Lens

• Has a variable shape, allowing it to focus objects at different distances on both its front and back surfaces
• Is more curved at the back than the front
• Has a smaller focusing power compared to the cornea due to being surrounded by substances with similar refractive indexes
• Composed of layered structures, similar to an onion, with varying refractive indexes

The Aqueous Humor

• Fills the space between the lens and the cornea
• Composed mostly of water, with a refractive index of approximately 1.33
• Continuously produced and drained through the "Canal of Schlemm" to maintain a balance
• Blockage of the drain tube can lead to increased pressure in the eye, resulting in Glaucoma
• Maintains the internal pressure of the eye at around 20mm Hg
• Provides nutrients to the non-vascularized cornea and lens, containing components similar to blood

The Vitreous Humor

• A clear, jelly-like substance filling the space between the lens and the retina
• Helps maintain the shape of the eye and is essentially permanent

The Sclera

• No significant information provided

This quiz covers the structure and function of the lens and aqueous humor in the human eye, including their roles in vision and focus.