Lens Technologies. Microscopes. Invented by Johannes and Zacharias Jansen in 1590 Larger inverted image Used in study of cells and diseases. Refracting Telescopes: Galileo and Kepler. Reflecting Telescope: Newton’s Innovation. Reduced chromatic aberration. Modern Telescope.
Ciliary muscles make the lens shorter and thicker to focus a nearby object
Relaxed eye lens focusses on a distant object
Common causes of poor vision: