Anatomy of the Eye

Structure of the Eye

• The eye is a spherical organ consisting of three layers:
  • Outer layer: sclera and cornea
  • Middle layer: choroid, ciliary body, and iris
  • Inner layer: retina

Cornea

• Transparent, dome-shaped surface at the front of the eye
• Responsible for refracting light
• Composed of five layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium

Iris

• Colored part of the eye
• Controls the amount of light entering the eye by adjusting the size of the pupil
• Consists of two types of smooth muscle: radial and circular

Lens

• Biconvex, transparent structure behind the iris
• Changes shape to focus light on the retina
• Suspended by zonular fibers

Retina

• Innermost layer of the eye
• Contains two types of photoreceptors: rods and cones
• Rods are sensitive to low light levels, while cones are responsible for color vision

Optic Nerve

• Carries electrical signals from the retina to the brain
• Consists of axons of retinal ganglion cells
• Transmits visual information to the lateral geniculate nucleus and then to the visual cortex

Extraocular Muscles

• Six muscles that control eye movements:
  • Lateral rectus
  • Medial rectus
  • Superior rectus
  • Inferior rectus
  • Superior oblique
  • Inferior oblique

Vision Process

• Light enters the eye through the cornea
• Light is refracted by the lens and focused on the retina
• Photoreceptors (rods and cones) convert light into electrical signals
• Signals are transmitted to the brain via the optic nerve
• Brain interprets visual information and creates a visual representation of the world

Structure of the Eye

• The eye consists of three layers: sclera and cornea (outer), choroid, ciliary body, and iris (middle), and retina (inner)
• Each layer has specific functions and components

Cornea

• The cornea is a transparent, dome-shaped surface at the front of the eye
• Responsible for refracting light
• Composed of five layers: epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium

Iris

• The iris is the colored part of the eye
• Controls the amount of light entering the eye by adjusting the size of the pupil
• Consists of two types of smooth muscle: radial and circular

Lens

• The lens is a biconvex, transparent structure behind the iris
• Changes shape to focus light on the retina
• Suspended by zonular fibers

Retina

• The retina is the innermost layer of the eye
• Contains two types of photoreceptors: rods and cones
• Rods are sensitive to low light levels, while cones are responsible for color vision

Optic Nerve

• The optic nerve carries electrical signals from the retina to the brain
• Consists of axons of retinal ganglion cells
• Transmits visual information to the lateral geniculate nucleus and then to the visual cortex

Extraocular Muscles

• There are six muscles that control eye movements: lateral rectus, medial rectus, superior rectus, inferior rectus, superior oblique, and inferior oblique
• Each muscle has a specific function in moving the eye

Vision Process

• Light enters the eye through the cornea
• Light is refracted by the lens and focused on the retina
• Photoreceptors (rods and cones) convert light into electrical signals
• Signals are transmitted to the brain via the optic nerve
• The brain interprets visual information and creates a visual representation of the world

This quiz covers the structure of the eye, including the cornea and iris, and their roles in vision.