Physiology of Vision: Structure and Function of the Eye

Introduction

The human eye is a highly specialized organ designed to detect and process light, enabling vision. Understanding its structure and function helps in diagnosing and managing various ophthalmic conditions.

Structure of the Eye

Cornea and Lens

• Cornea: The transparent outer layer that refracts light into the eye.
• Lens: A flexible structure that further refines light focus onto the retina.

Retina and Optic Nerve

• Retina: Houses photoreceptors—rods and cones—that detect light and color.
• Optic Nerve: Transmits visual information to the brain.

Function of the Eye

Light Transmission and Refraction

Light enters the eye through the cornea, passes through the lens, and focuses onto the retina.

Visual Signal Processing

Photoreceptors convert light into electrical signals, which travel via the optic nerve to the brain’s visual cortex for interpretation.

Common Vision Disorders

Refractive Errors

• Myopia (nearsightedness)
• Hyperopia (farsightedness)
• Astigmatism

Neurological Disorders

• Glaucoma – Increased intraocular pressure damaging the optic nerve.
• Macular Degeneration – Loss of central vision due to retinal damage.

Conclusion

The physiology of vision is essential for maintaining optimal eye health. Regular eye exams and early intervention are key in managing vision disorders effectively.