Definition of optical in English:



  • 1Relating to sight, especially in relation to the physical action of light.

    ‘optical illusions’
    • ‘Radio astronomy is a young field relative to optical astronomy.’
    • ‘Not only did Leonardo study the geometry of perspective but he also studied the optical principles of the eye in his attempts to create reality as seen by the eye.’
    • ‘Strobes and pyrotechnics nestle amongst shadow puppetry, while a vast array of other optical and audio effects assist in the delivery of this fast-moving tale.’
    • ‘The same optical illusion is in the second act.’
    • ‘The new system should help remove the optical trickery that occurs when assistant referees fail to position themselves correctly on the sidelines.’
    • ‘Hooper declared at the outset of his book that optical toys could hone visual perception and, consequently, prime social vigilance.’
    optical, seeing, optic, ocular, eye
    View synonyms
    1. 1.1Constructed to assist sight.
      • ‘Counting how many Pleiads you can see without optical aid is a good test of both your vision and observing conditions; most people see 6 or 7.’
      • ‘In addition, in bioengineering the low-power demands of this technology are promising for use in hearing aids and optical prosthetics.’
      • ‘For some, the use of optical aids compromises genius, and art with it.’
      • ‘Despite the efforts of some art historians to suggest that Vermeer literally transcribed what he saw with optical aids, such was not the case.’
      • ‘The controversy over the use of optical aids by early Renaissance painters is crossdisciplinary and emotionally charged.’
      • ‘You may be able to watch Jupiter disappear - an event known as immersion - without optical aid, though binoculars help.’
      • ‘The optical sight works either by using ambient light or under low light conditions, from a battery or tritium insert.’
      • ‘Normally, when Christine and I do any serious bird watching, it is with the Core Team and their plethora of optical aids and identification tomes.’
      • ‘This mismatch, he says, militates against the Hockney-Falco claim that the painter relied on optical aids.’
      • ‘Concerning the question of optical aids, there is a possible answer well short of the use of lenses, mirrors, or a pinhole camera obscura.’
    2. 1.2Devised on the principles of optics.
      • ‘The forward periscope is replaced by a passive optical periscope for night-time manoeuvres.’
      • ‘An optical lattice is a light grid created by the interference of two or more laser beams.’
      • ‘Created with a rear-screen optical printer and mattes cut out of construction paper, A Man Whose Life Was Full of Woe has a rough, ecstatic collage quality.’
      • ‘Currently, most optical fibers are made of solid glass, with pulses of light traveling through the core.’
      • ‘You can operate an optical telegraph as used in the Napoleonic wars, crank up second world war field telephones and learn to read Morse and semaphore.’
  • 2Physics
    Operating in or employing the visible part of the electromagnetic spectrum.

    ‘optical telescopes’
    • ‘The paper shows that positrons can see defects better than either optical or electron beam microscopes.’
    • ‘Whether the telescope is operating as an optical or an infrared instrument, rarely will there be an astronomer peering through an eyepiece at the Keck's images.’
    • ‘Of course, the capabilities of optical and infrared telescopes also continued to improve.’
    • ‘An optical light microscope or a scanning electron microscope can be used to see these ‘invisible’ cracks.’
    • ‘In medium- and high-grade metamorphic terrains, these studies can be adequately accomplished with the aid of optical microscopy.’
    1. 2.1Electronics (of a device) requiring electromagnetic radiation for its operation.
      ‘integrated optical circuits’
      • ‘Here's a look at how test sequencers can speed up tests on optical devices, saving time and money.’
      • ‘Available optical devices such as CDs and DVDs record information on the surface of the disc.’
      • ‘Unlike its electrical predecessor, an optical switch does not convert the signal to an electrical impulse before directing it.’
      • ‘But you can easily add another hard drive, drop in a graphics card or add a new optical drive.’
      • ‘Such a device might one day become the CPU of an optical computer.’