BIOLOGY · INTERACTIVE ANATOMY
Click, drag and zoom through a labeled cross-section of the human eye. Tap any structure to learn its job — then play with light and focus to watch the eye respond live.
LIVE · RUNS FULLY IN YOUR BROWSERThis is not a picture — it's an instrument. Fourteen structures, each one tappable, with a lens that reshapes, a pupil that breathes, and light rays you can follow all the way to the retina.
DRAG TO PAN · SCROLL OR PINCH TO ZOOM · TAP A STRUCTURE FOR DETAILS
Indoor light — the pupil holds a comfortable mid size.
Distant view — the ciliary muscle relaxes, the zonules pull tight, and the lens is stretched flat. Parallel rays still land on one sharp point.
The diagram rewards curiosity. Everything below works with a mouse, a trackpad, or a thumb.
Fourteen structures, from cornea to optic nerve. Tap one to load its job, its coat and one fact you won't forget — the rest of the eye steps aside so you can see it.
Pan the cross-section like a map. Scroll, pinch or use the corner buttons to zoom in — close enough to count the ciliary processes.
Drag the light slider from near-dark to daylight and watch the iris fold the pupil from 8 mm down to 2 mm, with a live readout underneath.
Switch between a distant and a close object. The lens rounds up, the zonules slacken, and light rays stay locked on one sharp point of the retina.
Reading the diagram is easier once you know what it's really showing. These are the three ideas the whole picture hangs on.
The cornea does about two-thirds of the bending; the lens fine-tunes the rest. Rays from one point on an object cross back to a single point on the retina — flipped upside down, as the little arrow in the diagram shows.
Your lens hangs in a muscular hammock. For near work the ciliary ring tightens, the suspension goes loose, and the lens bulges into a stronger shape. For distance, everything relaxes and the lens is pulled flat. Try it with the focus control above.
Where a million fibres exit the eye, there's nothing left to catch light — yet you've never noticed a hole in your vision. That's your brain stitching over the gap, using the other eye and educated guesswork.
Everything you can tap in the diagram, ordered the way light travels. Tap any chip to jump back up and open it.
3 COATS · 2 CHAMBERS · 1 CABLE TO THE BRAIN
Tap or click any structure — cornea, lens, retina, anything — to see its name, what it does, and a quick fact. Drag to look around, scroll or pinch to zoom, and use the quick-select list to jump straight to any part.
No. It's a stylized cross-section drawn for clarity — a real eye is about 24 mm across, structures overlap more, and the anterior chamber is proportionally smaller. Shapes and positions follow real anatomy so everything is recognizable, but it's an illustration, not a microscope photo.
You're testing the pupil reflex. In dim light the iris dilator muscle pulls the pupil open to about 8 mm; in bright light the sphincter muscle squeezes it down to about 2 mm. Watch the iris fold and the live millimetre readout change as you drag.
Accommodation — the way your lens changes shape. For a distant object the ciliary muscle relaxes and the zonules pull the lens flat; for close work the muscle contracts, the zonules go slack, and the lens rounds up. Follow the light rays either way: they always converge into a sharp spot on the retina.
Because the lens crosses light rays over — the top of any object you look at projects onto the lower retina, and vice versa. Your brain re-flips it so the world feels right-side up. The little arrow in the diagram shows the inverted image.
The optic disc — the pale patch where a million nerve fibres gather to leave the eye as the optic nerve. There are no photoreceptors there, so light landing on it is simply never seen. Your brain fills the gap using the surrounding view.
No. The whole diagram runs in your browser. Nothing you click, zoom or slide is ever sent to a server, logged or stored.
Yes to both. Tapping selects a structure, dragging pans the view and pinching zooms — it works the same with touch as with a mouse. And it's completely free: no account, no sign-up, no watermark, no limits.