Why Do Some Glasses Make Your Eyes Look Bigger?

We've looked at why some prescription glasses can make the eyes appear smaller. But glasses can also create the opposite effect.

With certain prescriptions, your eyes may appear slightly larger when somebody looks at you through your lenses.

Your eyes haven't actually changed size. It's an optical effect created by the lenses.

Why can glasses make your eyes look bigger?

This effect is mainly associated with plus prescription lenses.

Plus lenses are commonly used to correct long-sightedness and can also form part of prescriptions intended for near vision.

These lenses magnify what is viewed through them.

When another person looks at your eyes through the lenses, that magnification can make your eyes appear slightly larger.

Does a stronger prescription make the effect more noticeable?

Generally, yes.

With a relatively low plus prescription, the magnification may be so subtle that it's barely noticeable.

As the plus power increases, the effect can become more apparent.

This is why people with stronger plus prescriptions may notice a greater difference in how their eyes look when wearing their glasses.

Do glasses actually make your eyes bigger?

No.

Your glasses don't physically alter the size or shape of your eyes.

The effect exists because somebody is viewing your eyes through powered lenses.

When you remove the glasses, the magnification disappears.

Why can the face look slightly different through the lenses?

With stronger prescriptions, you may sometimes notice a small visual change where parts of the face are seen through the lenses.

This is another optical effect produced by the prescription.

It's particularly noticeable around the edges of some stronger lenses.

Can your choice of frame make a difference?

Frame choice can influence the overall appearance of your finished glasses.

With stronger prescriptions, choosing a frame that fits appropriately and positions your eyes well within the lens openings can be helpful.

Extremely large frames aren't automatically the best choice for every prescription.

Frame size, shape and your individual measurements all contribute to the final result.

What about lens index?

Higher-index lens materials can help reduce the thickness of lenses for suitable prescriptions.

This can improve the cosmetic appearance of stronger prescription glasses.

However, a thinner lens material doesn't remove the optical power required to correct your vision.

Some magnification may therefore still be visible.

Why do minus lenses make eyes look smaller instead?

Minus and plus lenses behave differently.

Minus lenses, which are commonly prescribed for short-sightedness, create a minifying effect.

Plus lenses create a magnifying effect.

That's why two people wearing similar-looking frames can have very different appearances through their lenses depending on their prescriptions.

Is eye magnification something to worry about?

No.

It's a normal optical consequence of certain prescriptions.

The purpose of your glasses is to provide the correction your eyes need, and some prescriptions naturally create more visible magnification than others.

For many people, the effect is relatively subtle.

Your prescription makes every pair unique

Two identical frames can look surprisingly different once prescription lenses are fitted.

Lens power, lens material, frame dimensions and individual measurements all contribute to the finished appearance.

If your eyes look slightly larger through your glasses, they're not actually changing size.

You're simply seeing one of the optical effects that allows your lenses to correct your vision.