Lab: Intro of the eye

Understanding Light Waves and Their Properties

• Light Waves: A form of electromagnetic radiation that is perceived by the eyes.

• Frequency: Determines color interpretation; higher frequency correlates to blue light, while lower frequency corresponds to red light.

• Amplitude: Refers to the height of the waves; larger amplitude results in brighter light, while smaller amplitude equates to darker light.

Anatomy of the Eye

• Accessory Structures: Produce lacrimal fluid, essential for eye lubrication and irritation prevention.

  • Lacrimal Fluid: Helps keep the eyes moist and is involved in the tearing process.

• Eye Positioning: The area around the eye includes medial (inner) and lateral (outer) parts.

• Medial Commision: The corner of the eye where lacrimal fluid collects.

Lacrimal System

• Lacrimal Gland: Produces lacrimal fluid.

• Excretory Ducts: Transport lacrimal fluid across the eye.

• Lacrimal Punctum and Caruncle: Structures on the medial side of the eye aiding in fluid drainage.

Structure of the Eye

• Pupil: The opening that controls light entering the eye.

  • Iris: Determines pupil size, controlling the amount of light entering; can dilate or constrict based on light levels.

Layers of the Eye

• Cornea: The outermost transparent layer, acting as a barrier and projection surface for light.

• Sclera: White protective layer surrounding the eye.

• Choroid: Beneath the sclera, provides oxygen and nutrients to the eye tissues.

• Retina: The inner layer containing photoreceptors; processes light signals to send to the brain.

Photoreceptors and Signal Processing

• Photoreceptors: Located in the retina, consisting of two types: rods and cones.

  • Rods: Sensitive to light; provide night vision and grayscale perception.

  • Cones: Responsible for color vision; three types include blue, green, and red cones.

• Bipolar Cells: Intermediary neurons between photoreceptors and ganglion cells.

• Ganglion Cells: Receive signals from bipolar cells and form the optic nerve that transmits visual information to the brain.

Nervous System and Light Reception

• Optic Nerve: Transmits visual signals to the brain's primary visual cortex.

• Optic Disc: Area in the retina where the optic nerve exits, resulting in a blind spot.

• Neuronal Arrangement: Photoreceptors send signals backward to retinal ganglion cells, traveling through the optic nerve to convey visual information.

Eye Movement Mechanism

• Extraocular Muscles: Control eye movement, enabling up, down, left, and right motion.

  • Muscles include Medial Rectus, Lateral Rectus, Superior Rectus, and Inferior Rectus.

  • Oblique Muscles: Help facilitate diagonal movement of the eye.

• Movement is a result of muscle contractions, altering the position of the eye for visual tracking.