This is a beta course, so its structure, chapters, and examples may continue to change.
The Optical Structure of the Eye
The human eye is like a small camera with “built-in autofocus”: the cornea and lens form the lens system, the vitreous body acts as the medium, and the retina is the photosensitive surface where the image forms.
Cross-section of the eye (cornea, lens, retina, macula)Eye anatomy
- The cornea and the lens together perform the refracting and focusing.
- The retina is the light-sensitive layer; the macula provides fine visual acuity.
- The optic nerve carries the signal to the brain, completing visual perception.
- Cornea: one of the main sources of refractive power, with a fixed curvature.
- Lens (crystalline lens): its curvature can be adjusted (accommodation), “auto-zooming” when you look far away and close up.
- Pupil: controls how much light enters and increases depth of field.
- Macula (fovea): the region with the highest resolution, which determines our fine visual acuity.
- Retina and optic nerve: convert light signals into electrical signals and pass them to the brain.
Understanding the optical structure of the eye helps you see exactly where in the light path myopia, hyperopia, and astigmatism occur.