Hyperopia (Far-Sightedness)

The Projector with the Lens Too Far Back

Imagine a movie projector where the film strip (object you're looking at) sits close in front, and the lens (cornea + lens) bends light onto a screen (retina) at the back of a box. In a normal eye, the lens bends light just enough so the focused spot lands exactly on the screen. In hyperopia, the box is too short front-to-back (short eyeball), or the lens is too weak to bend light sharply enough (flat cornea or weak lens), so the light rays are still spreading apart when they hit the screen—they haven't converged yet. The focal point would land behind the screen if it extended back that far. When you show a close-up slide (near object), the light spreads even wider, so the lens has to work harder (accommodation = squeezing the lens rounder) to pull the focus forward. But over time, the lens gets stiff (presbyopia), squeezing doesn't help anymore, and the image stays blurry on the screen without external correction (glasses that do the bending the lens can't).