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Show HN: Eyeball

295 pointsby mrroryflint06/02/202688 commentsview on HN

Comments

MontyCarloHall06/02/2026

A modern take on Matthias Wandel's classic [0], which has you guess a variety of geometric attributes (e.g. angle bisection, centroid locating, shape regularization), not just simple partitioning of a line.

[0] https://woodgears.ca/eyeball/index.html

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forlorn_mammoth06/02/2026

Love it!

It would be great to have a 'training' mode, where you get to repeat ones you miss. This would increase the learning speed.

Easy training- repeat the one you just borked Medium training- cycles through say 5 examples until you get all five within your target range (1%, 0.1%, whatever)

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sandebert06/02/2026

Got a perfect result for the first try. (Off by zero.) Not trying again. :)

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davidcollantes06/02/2026

I was 0.06% off on eyeball. Beat me: https://eyeball.rory.codes.

This is fun!

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harrisi06/02/2026

It's interesting that there are, at the time I'm commenting, 11 new users commenting on this submission, some commenting multiple times. I wonder what the effect of "share my score" type pages have on account creation.

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zer0tonin06/02/2026

This is fun but you need to put "click the line" higher on the page. It took me a while to figure out what I was looking at.

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densekernel06/02/2026

https://eyeball.rory.codes/ I was 0.20% off on eyeball. Beat me: https://eyeball.rory.codes

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mavdol0406/03/2026

It's a bit of a cheat, but you can hit 0.00% every time. Just measure the bar length, then cross-multiply. :)

Example: bar is 1250px, max is 2100, number is 376 → (1250 × 376) / 2100 ≈ 223.8px from the start, that's the 0.00%.

throwawaydudhdn06/02/2026

Great idea! Have you considered storing triplets <range, correct number, selected number> for each try and making image plots of these (x/y coordinates are correct/selected numbers, color of each pixel represents frequency) for multiple users for each range? I think the image might reveal interesting properties of human eyeballing, like near-perfect accuracy around 50%, but with less obvious correlations.

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layer806/02/2026

The fact that the numbers are in a brighter color than the end marks, and that the numbers go inwards, makes it slightly more difficult than it would otherwise be, because the eye is biased by the more prominent space between the numbers being different from the line between the marks.

pedromlsreis06/02/2026

0.11% by luck, because I actually got lucky the target number was too close to zero, out of a big scale.

SugarReflex06/04/2026

I thought this was a random guessing game and kept randomly clicking and felt very frustrated. Once I realized how it works with the two numbers, estimating felt a lot more rewarding.

ashm110406/02/2026

I love these kind ones! Really engaging also yes as someone commented, the training mode would be an awesome idea.

Also, I tried this on laptop as well as my phone, I liked it more on my phone (I know the whole point is about precision though)

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furyofantares06/02/2026

I find it very easy if it's near 50%, 10%, or 5%.

Presumably I'd do just as well visually near 90 and 95 as near 10 and 5, the difference is in the first stage, estimating the percentage.

iJohnDoe06/03/2026

This seems like a nice therapeutic application. Something a person or practitioner could say, “Sit down and play this for 5 minutes to calm your mind.”

ninju06/02/2026

Note the "share" link doesn't share a specific challenge for others to try, which would be much cooler, instead it just shares to main page

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obomeretic06/03/2026

I was 0.67% off on eyeball. Beat me: https://eyeball.rory.codes

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joey9prints06/02/2026

Cool idea, love how simple it is. Minimal and clean.

gverrilla06/02/2026

Suggestion: make timed tracks - like a sequence of 10 turns, within max 60/30/15s or something.

Mabusto06/02/2026

I love these simple games that take 2 seconds to understand the rules.

Off by 6 on my iPad by mis-clicking. Very satisfying!

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FinanceFreddy06/02/2026

Oh, this is actually fun! How about if you change the target every few seconds to add a bit of pressure.

schuhwerk06/02/2026

Nice! Would be nice to see your progress over time (if you got better, also as a function of speed...)

fortran7706/02/2026

I got a perfect "off by 4" on the first try! I feel like I've accomplished something!

RAZKOM06/02/2026

I thought I was going to be really good at this but turns out I'm surprisingly bad. Cool idea.

ketul_shah06/02/2026

this is fun and helping me get grounded :). adding a timer would be a good idea, I think.

zokier06/02/2026

10 round avg 4.5%.

A time limit would make sense imho. For extra challenge, add diagonal or curved lines.

tartoran06/02/2026

Fun. Got a streak of 4 and one of them was perfect (nearly .10% of target).

sentacraft06/04/2026

This is fun! and I really love the clean and modern UX.

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Kwouz06/04/2026

Its cool man, i was playing for 1 hour, havent won yet

0xchamin06/04/2026

cool game. I tried. would be nice to include a helper description around what to do. took me a while to understand the challenge better.

p2hari06/02/2026

My best on first attempt was 0.00% (Pure coincidence) . But was fun!

0x000xca0xfe06/02/2026

10 perfect hits in a row!

...

handleClick({clientX: els.bar.getBoundingClientRect().left + els.bar.getBoundingClientRect().width / state.n * state.target })

ramon15606/02/2026

800

0 out of 1,600

I still missed. Even when there was centered text.

Maybe the human is the weakest link

wolttam06/02/2026

The low contrast of this website hurts my eyeball

baisampayans06/02/2026

This is wild. Got hooked into it pretty fast

untitled-now06/02/2026

I am amazed how such a simple app gets that much attention , whereas probably it is vibe coded in an hour using Claude or any other AI tool .

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lbeyer06/02/2026

Simple premise, oddly hard to put down.

shashankqv06/02/2026

This is very cool and fun. Thank you.

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Lucas1254606/04/2026

I got 0.03%. I try my best.

ehsangazarr06/02/2026

Really fun! I am pretty much blind

efilife06/04/2026

very weird comments from very fresh accounts under this post

Chaseraph06/02/2026

Well I suck.

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fspoettel06/02/2026

Would love a time trial mode

Daniel-Pan06/05/2026

I was 0.43% away

dennis312406/02/2026

Love how simple it is.

jjenks110606/02/2026

really cool! enjoy the simple premise but very satisfying

antoine-codefly06/02/2026

Definitely need an iOS version! An angle version on a circle would be nice too.

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thedetailsguy06/02/2026

Super cool stuff!

oastp06/02/2026

love it, pulls you in after a first try)

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