lens

lens — noun

1. A piece of curved glass or other clear material that brings light rays together

1.nounA2
Definition

A piece of curved glass or other clear material that brings light rays together or spreads them apart, used in things like cameras, glasses, telescopes, and microscopes to make images appear clearer, larger, or smaller.

Example

Mia cleaned the camera lens with a soft cloth before taking the photo.

collocation: clean a lens / scratch a lens

The telescope lens was cracked, so the stars appeared blurry to Tunde.

Common collocations
  • camera lens
  • eyeglass lens
  • magnifying lens
  • zoom lens
  • wide-angle lens
  • lens cap
  • lens cleaner
Synonyms
  • optic

    Technical term for an optical lens or component, used mainly in scientific or formal writing

Grammar Patterns

lens + for [purpose]

lens of [device]

Usage Note

Frequently combined with a noun describing the device (camera lens, eyeglass lens, microscope lens) or the purpose (zoom lens, wide-angle lens).

Common Mistakes

I need to buy a new glass for my camera.
I need to buy a new lens for my camera.
In English, a camera uses a 'lens', not a 'glass', even though it is made of glass or plastic.

2. A very small, thin piece of clear plastic that is worn directly on the surface o

2.nounA2
Definition

A very small, thin piece of clear plastic that is worn directly on the surface of the eye to help a person see more clearly, as an alternative to wearing glasses.

Example

Folake takes out her contact lenses every night before she goes to sleep.

verb pattern: take out + contact lenses

Roya prefers contact lenses over glasses because they do not fog up during exercise.

Common collocations
  • contact lens solution
  • wear contact lenses
  • put in contact lenses
  • take out contact lenses
  • soft contact lenses
  • daily contact lenses
Synonyms
  • contact

    Informal short form of 'contact lens', common in casual speech ('I need new contacts').

Grammar Patterns

wear + contact lenses

put in + contact lenses

take out + contact lenses

Usage Note

Almost always used in the plural form 'contact lenses' even when referring to a single pair. Use 'contact lens' (singular) when referring to one individual lens.

Common Mistakes

I wear contacts lens.
I wear contact lenses.
The word 'contact' is an adjective here; the noun 'lenses' must be plural when referring to both eyes.

3. A clear, bendy structure inside the eye, positioned behind the iris, that alters

3.nounB2
Definition

A clear, bendy structure inside the eye, positioned behind the iris, that alters its shape to guide incoming rays toward the retina for clear sight.

Example

As people grow older, the lens of the eye can become cloudy, causing cataracts.

noun phrase: the lens of the eye

Amihan learned how the lens works with the cornea to focus images on the retina.

Common collocations
  • lens of the eye
  • crystalline lens
  • lens capsule
  • lens flexibility
  • cloudy lens
Synonyms
  • crystalline lens

    Formal anatomical term for the lens of the eye, used in medical and scientific writing

Grammar Patterns

the lens of the eye

lens + becomes/is [adjective]

Usage Note

Frequently preceded by 'the' in scientific or medical contexts ('the lens', 'the lens of the eye'). Distinguished from the 'contact lens' sense by the definite article and anatomical context.

Common Mistakes

The contact lens in my eye is getting cloudy with age.
The lens in my eye is getting cloudy with age.
'Contact lens' refers to the removable plastic device; the natural eye structure is simply 'the lens' or 'crystalline lens'.

4. A particular way of thinking about or understanding a situation, problem, or ide

4.nounB2
Definition

A particular way of thinking about or understanding a situation, problem, or idea, as if looking at it from a specific point of view — for example, considering an issue through the lens of history, economics, or personal experience.

Example

The documentary examined the war through the lens of ordinary people trying to survive.

metaphorical pattern: through the lens of [someone/something]

Esme's experience of living in three countries gives her a unique lens on cultural differences.

Common collocations
  • through the lens of
  • historical lens
  • critical lens
  • cultural lens
  • analytical lens
Synonyms
  • perspective

    Broader and more common in everyday speech; does not carry the optical metaphor as strongly

  • viewpoint

    More direct and less formal; suggests a specific person's or group's position

  • angle

    Suggests a particular slant or emphasis, often in journalism or debate

Grammar Patterns

through the lens of [something]

from a [adjective] lens

Usage Note

Almost always follows the preposition 'through' (through the lens of...). The modifying word or phrase describes whose perspective or what framework is being adopted. Common only in formal or analytical writing.

Common Mistakes

I see it with a different lens.
I see it through a different lens.
The fixed preposition is 'through', not 'with'.

5. A device that uses magnetic or electric fields to direct and concentrate a strea

5.nounC1
Definition

A device that uses magnetic or electric fields to direct and concentrate a stream of particles or waves, such as electrons in an electron microscope or protons in a particle accelerator.

Example

An electron microscope uses magnetic lenses to focus a beam of electrons instead of light.

noun phrase: magnetic lens / electron lens

The scientists adjusted the lens in the particle accelerator to keep the proton beam stable.

Common collocations
  • electron lens
  • magnetic lens
  • electrostatic lens
  • focus a beam
  • particle accelerator

Grammar Patterns

magnetic + lens

electron + lens

Usage Note

Almost exclusively used in scientific and technical contexts. Often paired with the type of field ('magnetic lens', 'electrostatic lens') or the type of particle ('electron lens', 'proton lens').

lens — verb

Word family

  • lensed
    adjectiveC1
  • lensing
    nounC1
  • multilens
    adjectiveC2
  • telelens
    nounC1

Synonym discussion

Sense: noun/1

While all four words relate to optics, they refer to different things. A 'lens' is a curved transparent object that focuses or spreads light — the most general and common of the group. A 'prism' is a triangular block that splits light into colours (a rainbow effect); it does not form images the way a lens does. An 'optic' is a technical term for any optical component or system, often used in scientific writing ('fibre optic cable'), but rarely in everyday speech. A 'magnifier' is a specific type of lens designed to make objects look bigger, typically with a handle and used for reading fine print or examining details. In everyday language, if you need to see something more clearly, you use a 'lens' (in glasses) or a 'magnifier' (a handheld tool). If you want to study how light bends, you talk about a 'prism'. If you are discussing fibre-optic cables or laser systems, you might use 'optic'.

lens ↗prism ↗optic ↗magnifier

Common collocations

Nouns

Phrases

  • through the lens of
  • lens of the eye
  • focus the lens
  • adjust the lens
  • behind the lens

Prepositions

Etymology

LatinEnglish

The word 'lens' comes from the Latin word 'lēns', meaning 'lentil' — the small, round, flat seed of the lentil plant. Early eyeglass-makers in the 1600s noticed that the shape of the glass they were making looked like a lentil seed, and the name stuck. The same Latin root also gives us the word 'lentil' in English. The metaphorical sense ('through the lens of...') developed in the 1900s, borrowing the idea of an optical lens to describe how people see or interpret things differently.