What is astigmatism anyway? The things on the sides of glasses that hook onto your ears—what are those actually called?

No need to get intimidated when it comes to knowing vision vocab and eyewear words. Here is a simple guide to some common words you may not know.

 

astigmatism
Simply, astigmatism refers to the very common issue of your cornea or lens (parts of the eyeball) having mismatched curves. It’s similar to when you stack bowls from different dishware sets together and they don’t quite fit just right. This can cause blurred vision or other vision problems.

bifocal lenses
A type of glasses lens meant to correct both farsightedness and nearsightedness.

cataract
Proteins sometimes build up on the lens of the eye and create a cloudy spot—this is a cataract. Cataracts block light and cause other vision issues.

cornea
The cornea is the outer layer of the eye and helps to filter light.

farsightedness
When an individual is farsighted or has farsightedness, this means that text and objects close to them are blurry while text and objects further away are seen clearly. Farsightedness is sometimes called hyperopia.

iris
The coloured part of the eye. Its purpose is to control the size of the pupil which lets more or less light reach the retina. Think of them as the curtain of the eye.

nearsightedness
When an individual is nearsighted or has nearsightedness, this means they can see objects and text clearly when they are close to them but text and objects further away are blurry. Nearsightedness is sometimes called myopia.

optic nerve
The optic nerve is connected from the back of your eye to your brain. It transmits messages from the eyes to the brain using signals sent by the retina and other parts of the eye to tell the brain what images to display.

optician
Opticians are licensed eye healthcare professionals. They interpret prescriptions provided to a patient by an optometrist and help patients find the right corrective device for them: glasses, contacts, etc. They may also be involved in the manufacturing of lenses or glasses.

optometrist
An eye doctor who performs vision tests and prescribes corrective devices for vision.

ophthalmologist
An eye doctor who can perform eye surgery.

progressive lenses
A type of glasses lens. Similar to bifocal lenses, they correct for both farsightedness and nearsightedness. However, they also correct for vision issues the wearer might have seeing objects in the middle distance between near and far.

retina
Located at the back of the eye, the retina is a major part of the eye that processes light, what we see and how we see it. It connects to the optic nerve which travels to our brain and tells the brain what images to display for us. It is often compared to film in a camera.

single vision
A type of glasses lens meant to correct either nearsightedness or farsightedness but not both.

Snellen chart
These are the vision test charts used in optometrist offices. They display letters the test taker has to identify so the optometrist can identify vision issues. Vision tests for children too young to identify letters sometimes show shapes or symbols instead.

temples
Sometimes referred to as arms or bows, temples are the two side pieces on a pair of glasses that rest on the ears and connect to the hinges.