Optics

A flaw of about two micrometers left early images blurry until astronauts installed corrective optics in 1993.

The first wearable lenses appeared around 1286, long before the invention of the microscope or telescope.

In the early 11th century he argued that vision works by light entering the eye and used experiments to show it.

Where the optic nerve leaves the retina there are no light-detecting cells, but the brain fills in the gap.

Light refracts as it enters a drop, reflects off the back and splits into colors as it leaves.

Advanced polishing and deposition techniques allow for surfaces so smooth that irregularities are measured in angstroms, essential for technologies like computer chips and optical lenses.

Light travels fastest in a vacuum (about 299,792 kilometers per second). When it passes through denser mediums like water or glass, it interacts with the atoms, causing it to slow down temporarily.

When viewed from space, the Sun emits light across the entire visible spectrum, making it appear white. Its yellow appearance from Earth is due to atmospheric scattering, which removes blue light, making it seem warmer in color.

These involuntary movements, called microsaccades, tremors, and drifts, are essential for preventing your vision from fading. Without them, your brain would adapt to a static image and stop perceiving it, highlighting dynamic visual processing.

Due to the way Martian dust scatters light, the blue light penetrates the atmosphere more efficiently than other colors. This creates a striking blue hue around the setting sun, a stark contrast to Earth's familiar red sunsets.