optical

Everyday

1. To do with seeing and the eyes. tree →
2. To do with light and how it travels, or with instruments that use light, such as lenses, microscopes and telescopes. tree →

In the lessons

In science, «optical illusion» is a picture that tricks your eyes and brain; «optical fibre» carries light (and internet data) along thin glass threads. Opticians sell glasses. Phrases: «optical illusion», «optical fibre», «optical instrument», «optical mouse».

Examples

• The picture is an optical illusion: the two lines look different but are the same length. tree →
• Optical fibres carry internet signals as flashes of light. tree →
• A telescope is an optical instrument. tree →
• The optical mouse uses a tiny light to see movement. tree →
• Optical shops sell glasses and contact lenses. tree →
• The magician used optical tricks with mirrors. tree →

Note

Adjective. Related: optician (a person who tests eyes and sells glasses), optics (the science of light). UK spelling «optical fibre», US «optical fiber». Trap: «optical» is about sight and light, not «optional» (you can choose).

In Jewish tradition

In science, «optical illusion» is a picture that tricks your eyes and brain; «optical fibre» carries light (and internet data) along thin glass threads. Opticians sell glasses. Phrases: «optical illusion», «optical fibre», «optical instrument», «optical mouse».

Note

Adjective. Related: optician (a person who tests eyes and sells glasses), optics (the science of light). UK spelling «optical fibre», US «optical fiber». Trap: «optical» is about sight and light, not «optional» (you can choose).