'Convex Lens' vs 'Concave Lens': What's the Difference?

‘Convex Lens’ vs ‘Concave Lens’: What’s the difference? Sometimes, when we learn new vocabulary, it can also be a great review of the grammatical structures that help us connect words. Let’s go beyond definitions and explore the ins and outs of how language is formed by learning ‘Convex Lens’ vs ‘Concave Lens.’

Are you in a rush? Here’s a preview of what’s to come:

• ‘Convex Lens’ is a word that means a lens that curves outward around the middle
• ‘Concave Lens’ is a word that means a lens that curves inward at the center

What’s the Difference Between ‘Convex Lens’ vs ‘Concave Lens’?

Before diving into the difference between these two, let’s first acknowledge how they are similar. The word ‘Lens’ appears in both terms, so we can define that individually first.

According to Oxford Languages, ‘Lens’ is a noun that means:

• A piece of glass or transparent substance with curved sides for concentrating or dispersing light rays used singly (to magnify) or with other lenses (like a telescope)

Many things can have lenses, such as cameras, periscopes, and even our eyes. But, as the title of this article may suggest, different kinds of lenses have unique functions. It is important to note that ‘Lens’ is a noun, meaning it is an object that can be modified by words around it, like, for example, ‘Convex’ vs ‘Concave.’

• ‘Convex’ and ‘Concave’ are both adjectives, meaning they can modify and add a description to the word ‘Lens,’ which helps us distinguish them. 
• ‘Convex’ and ‘Concave’ are also antonyms, meaning they describe opposites. 

Many things can have lenses, such as cameras, periscopes, and even our eyes. But, as the title of this article may suggest, different kinds of lenses have unique functions. 

‘Convex Lenses’ vs ‘Concave Lenses’ are tasked with different things, and before we learn about them by themselves, let's see how they compare to each other. The first difference is their shape.

• A ‘Convex Lens’ curves outward so the middle is thicker and the edges come to a point.
• A ‘Concave Lens’ curves inward, and the middle is the thinnest part, meaning the edges form a bowl shape. 

The shape being the primary visible difference between these two terms leads to the next distinction — they have different effects on light.

• A ‘Convex Lens’ converges rays of light to one point.
• A ‘Concave Lens’ diverges rays of light and splits them across an area

Understanding the key differences between these terms helps us visualize how they compare, but they don’t give us a full picture of the words individually. So, let’s take a deep dive into the meanings of ‘Convex Lens’ vs ‘Concave Lens’ one at a time. 

Definition of ‘Convex’: What Does it Mean?

According to Oxford Languages, ‘Convex’ is an adjective that means:

• Having an outline or surface curved like the exterior of a circle or sphere 
  • “Convex mirrors in a parking lot.”
• (of a polygon) having only interior angles measuring less than 180 degrees

The word ‘Convex’ comes from the Latin root ‘convexus,’ which means “vaulted” or “arched,” which is likely linked to the dome-like ceilings that were common in the Roman Empire, which had a convex shape. 

Synonyms of ‘Convex’

• Rounded
• Bulging
• Curving outward
• Arched
• Bent
• Gibbous
• Dome-like 

Antonyms of ‘Convex’

• Concave
• Sinking
• Depressed
• Bowl-shaped

Definition of ‘Convex Lens’: What is it?

According to the Physics Dictionary, ‘Convex Lens’ is a noun that means:

• A lens that converges rays of light that convey parallel to its principal axis, which is relatively thick across the middle and thin at the lower and upper edges; the edges are curved outward
  • “Eye contacts are convex lenses.”

Definition of ‘Concave’: What Does it Mean?

According to Oxford Languages, ‘Concave’ is an adjective that means:

• Having an outline or surface that curves inward like the interior of a circle or sphere 
  • “They used a concave surface.”
• Hollowed or rounded inward like the inside of a bowl

The word ‘Concave’ comes from the Latin roots ‘con-’ which means “together” and ‘cavus’ which means “hollow.” You can also think about how' Concave' things tend to cave inwards, meaning they collapse in the middle rather than bulge out. 

Synonyms of ‘Concave’

• Curved inward
• Depressed
• Cupped
• Bowl-like
• Dented
• Dimpled
• Hollow
• Sunken
• Scooped
• Indented
• Crescent 

Antonyms of ‘Concave’

• Convex
• Bulging
• Distended
• Arched up
• Gibbous 

Definition of ‘Concave Lens’: What is it?

According to the Physics Dictionary, ‘Concave Lens’ is a noun that means:

• A lens that diverges a straight light beam from the source to a diminished, upright, virtual image, with the surface curved inside that is thinner in the middle and thicker on the edges
• Lenses that are formed by binding spherical surfaces such that they are curved inward

Pronunciations: How to Pronounce ‘Convex Lens’ vs ‘Concave Lens’ 

Writing is only part of language use. A lot of learning happens through speaking. Follow the guides below to learn how to properly pronounce ‘Convex’ vs ‘Concave’ and feel comfortable saying the words aloud. 

Use this phonetic spelling of ‘Convex Lens’ as a guide:

• ‘Kahn-vehx Leh-nz’ (the ‘o’ vowel is wide like in the word “icon,” and the ‘s’ at the end of ‘Lens’ is voiced like the ‘z’ sound)

Use this phonetic spelling of ‘Concave Lens’ as a guide:

• ‘Kahn-ca-v Leh-nz’ (the ‘ca’ is a bright sound like “wave,” and ‘Lens’ is the same as above)

How to Use ‘Convex Lens’ vs ‘Concave Lens’ in a Sentence

The final step to understanding a new word is being able to use it in your own scenarios. The example sentences below will give you an idea of how to use these new vocabulary words in a variety of contexts. 

‘Convex’ Example Sentences

• Convex shapes appear in all different areas of life, including sports, where a football is convex. 
• Many parking garages use convex mirrors to help people turn tight corners and be able to see around them without hitting other cars. 
• The metal hemisphere bulged out of the ground like a silver convex lump.

‘Convex Lens’ Example Sentences

• You can focus the power of many streams of light into one singular spot using a convex lens.
• The human eye is actually an example of a convex lens, specifically our cornea, which acts as a clear dome. 

‘Concave’ Example Sentences

• The best way to visualize a concave surface is to picture a bowl because it shows the inward curve. 
• The inside of a spoon can also be used as a form of concave mirror, although your reflection will be distorted. 
• The ground had concaved inward where the boulder had fallen, and now there was a crater in its place. 

‘Concave Lens’ Example Sentences 

• People who are nearsighted often wear glasses that use concave lenses because they help focus the image of the world around them. 
• Telescopes, lasers, cameras, and binoculars are all instruments that use concave lenses. 

Final Advice on ‘Convex Lens’ vs ‘Concave Lens’

Learning new phrases can be complicated when you have to piece words together first. But when you start with what makes phrases similar, you can set those aside to focus on the distinctions. Remember that antonyms are your friend when it comes to telling words apart, and focusing on visible differences can help as well. 

Need a recap? Here’s a review of what was covered:

• ‘Convex Lens’ is a noun that refers to a lens that is curved outward or arched
• ‘Concave Lens’ is a noun that refers to a lens that is curved inward or sunken in 

Want to learn more about opposing phrases? Be sure to check out other confusing word articles where we cover grammatical differences and teach you how to apply vocabulary to the world around you. Writing can help connect you to all sorts of subject matter. You just have to keep exploring what interests you.