Eye Structure and Function

The eye is a sensory organ responsible for vision.
Photoreceptors within the eye detect light.
The eye is housed within the bony orbits of the skull, providing protection from impacts.
The eye has three distinct layers: fibrous, vascular, and inner.
Fibrous Layer:
- Composed of the cornea and sclera.
- Provides shape and structure to the eyeball.
- Sclera serves as an attachment point for extraocular muscles.
- Extraocular muscles control eye movement.
Vascular Layer:
- Contains:
  - Choroid: A network of blood vessels that supply the retina.
  - Iris: Controls the size of the pupil, regulating light entry.
  - Ciliary Body: Consists of muscles and processes.
    - Muscles attach to the lens via processes.
    - Produces aqueous humor.
    - Changes lens shape for accommodation (focus).
Inner Layer (Retina):
- The eye's sensory layer.
- Contains photoreceptors for light detection.
- Two layers:
  - Neural Layer: Thicker layer responsible for detecting photons.
  - Pigmented Layer: Thinner layer that supports the neural layer and absorbs stray light.
Macula and Fovea Centralis:
- Located at the center of the retina.
- Fovea has a high density of photoreceptors for sharpest vision.
Blind Spot:
- Located near the fovea.
- Lack of photoreceptors due to the optic nerve's exit point.
Vitreous Body:
- Transparent gel filling the posterior chamber of the eye (behind the lens).
- Contains the hyaloid canal, a fetal remnant.
Aqueous Humor:
- Clear fluid found in the anterior chamber (between the lens and cornea).
Lens:
- Located between the vitreous body and the pupil.
- Focuses light onto the retina.

Eye Structure and Function

The eye is a sensory organ responsible for vision, detecting light with photoreceptors.
The eye is housed within the bony orbits of the skull for protection.
The eye has three distinct layers: the fibrous, vascular, and inner layers.

Fibrous Layer

The fibrous layer consists of the cornea and sclera.
The cornea is the transparent outer layer, allowing light to enter the eye.
The sclera is the white outer layer, providing shape and structure to the eyeball.
The sclera serves as an attachment point for the extraocular muscles.
Extraocular muscles control eye movement, allowing for precise focus and tracking.

Vascular Layer

The vascular layer is composed of the choroid, iris, and ciliary body.
The choroid is a network of blood vessels that supply the retina with oxygen and nutrients.
The iris is the colored part of the eye, controlling the size of the pupil to regulate light entry.
The ciliary body consists of muscles and processes that attach to the lens.
Ciliary muscles change the shape of the lens for accommodation (focus).
The ciliary body produces aqueous humor, which fills the anterior chamber of the eye.

Inner Layer (Retina)

The inner layer, or retina, is the eye's sensory layer, containing photoreceptors for light detection.
The retina has two layers: the neural layer and the pigmented layer.
The neural layer is the thicker layer responsible for detecting photons and transmitting signals to the brain.
The pigmented layer is a thinner layer that supports the neural layer and absorbs stray light.

Macula and Fovea Centralis

The macula is located at the center of the retina, containing a high density of photoreceptors.
The fovea centralis is a small depression within the macula, responsible for sharpest vision.

Blind Spot

The blind spot is located near the fovea, where the optic nerve exits the eye.
There are no photoreceptors in the blind spot, resulting in a lack of visual perception in this area.

Vitreous Body

The vitreous body is a transparent gel filling the posterior chamber of the eye (behind the lens).
It contains the hyaloid canal, a small channel remnant from embryonic development.