Illusions Index
A philosophy department's catalogue of illusions, each with what it is, what it demonstrates, and the argument still going about it.
Opens in a new tab. We do not control this site and it may have changed since we catalogued it.
How to get the most from it
Illusions Index sits in Optical Illusions under Weird, filed as coffee break.
- Set aside five to fifteen minutes and give it your proper attention.
- It works on a phone or a desktop, so open it on whatever is nearest.
- It works with the sound off, so it is fine on a train or in a quiet office.
- No account needed — you can start without signing up.
- Go in expecting something brainy and clever.
About this category: Illusion collections and perception demos. The good ones keep working after you have been told exactly how they work.
Good for
- Filling a coffee break properly
- Giving your brain a workout
- Being impressed by a clever idea
- A quiet break at your desk
- Killing time on your phone
- Trying it with zero commitment
Illusions Index: quick answers
Is Illusions Index free?
Yes. Illusions Index is free to use and needs no account.
Do I need an account to use Illusions Index?
No. You can use Illusions Index without signing up for anything.
Does Illusions Index work on a phone?
Yes. Illusions Index works on phones as well as desktop browsers.
Is Illusions Index safe for work?
Yes, we file it as safe for work. It also works muted.
How long does Illusions Index take?
We file it as "Coffee break": Five to fifteen minutes of proper attention.
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