alt.hn

6/2/2026 at 9:04:49 AM

Show HN: Eyeball

 https://eyeball.rory.codes/

by mrroryflint

6/2/2026 at 2:46:43 PM

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

by MontyCarloHall

6/2/2026 at 5:10:53 PM

Oh that version actually made sense.

Going back to our newer game, I realized that I am supposed to figure out where the number given should fall on the line.

A case study in modern useability - looks a lot cooler, can't figure it out.

by kerblang

6/2/2026 at 3:18:33 PM

This is great. If only the little square tool would disappear while I make adjustments though - it's just enough of a distraction to barely miss.

by stronglikedan

6/2/2026 at 2:49:24 PM

Oh wow - that is very cool. Thanks for sharing.

by mrroryflint

6/2/2026 at 3:52:45 PM

Just want to say thank you for sharing your project. Very fun, and I wouldn't know about Matthias Wandel's version if not for yours!

Also, both of these tickled my brain in a great way. I think a potentially fun continuation would be to "eyeball" physics. For example, throw a ball and pause the physics before it hits something (ground, object, who knows?) and guess the location. Or show two objects about to collide with certain shapes and masses and guess what one of them will hit first and where.

by harrisi

6/2/2026 at 5:52:39 PM

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

by RAZKOM

6/2/2026 at 5:50:30 PM

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

by sandebert

6/2/2026 at 1:18:10 PM

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)

by forlorn_mammoth

6/2/2026 at 1:19:23 PM

Cool idea - thanks! I'm building a mobile app as we speak so I'll add it for sure.

by mrroryflint

6/2/2026 at 1:57:23 PM

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

This is fun!

by davidcollantes

6/2/2026 at 2:39:25 PM

> perfect - you picked 0 · off by 1 (0.03%)

by pelagicAustral

6/2/2026 at 3:20:43 PM

0.10%, but on a touch screen.

by layer8

6/2/2026 at 2:07:06 PM

Almost: 0.07%, allegedly 'perfect'. Getting an early win makes the game so much more 'playable'.

by Theodores

6/2/2026 at 2:32:34 PM

Why does an early win matter? Isn't it random?

by stavros

6/2/2026 at 5:24:38 PM

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

by p2hari

6/2/2026 at 4:30:49 PM

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.

by harrisi

6/2/2026 at 4:55:20 PM

yes, was thinking the same. but it's also weird that the amount of new users commenting is so much higher here. wonder if that is just not a coincidence.

by hazelnut

6/2/2026 at 3:17:35 PM

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.

by layer8

6/2/2026 at 4:30:32 PM

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

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

by Mabusto

6/2/2026 at 5:04:03 PM

Thank you!

by mrroryflint

6/2/2026 at 3:52:15 PM

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

by schuhwerk

6/2/2026 at 1:10:21 PM

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

by pedromlsreis

6/2/2026 at 2:40:31 PM

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.

by throwawaydudhdn

6/2/2026 at 2:48:21 PM

Very cool idea! Will try and add.

by mrroryflint

6/2/2026 at 1:30:15 PM

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)

by ashm1104

6/2/2026 at 1:41:29 PM

I'm* building an app currently!

*my old pal Claude

by mrroryflint

6/2/2026 at 4:10:15 PM

The low contrast of this website hurts my eyeball

by wolttam

6/2/2026 at 10:42:53 AM

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.

by zer0tonin

6/2/2026 at 2:02:18 PM

Just any kind of contrast between foreground and background would help.

by oneeyedpigeon

6/2/2026 at 11:24:24 AM

same happened to myself as well.

by ketul_shah

6/2/2026 at 2:01:19 PM

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

by joey9prints

6/2/2026 at 4:20:17 PM

Well I suck.

by Chaseraph

6/2/2026 at 4:21:10 PM

I built it and still suck, don’t feel so bad.

by mrroryflint

6/2/2026 at 4:50:09 PM

I didn't think I'd be any good at this. What I didn't expect is how wildly inaccurate I'd be on every single goddamn attempt lmao it's like I completely lack whatever part of your brain is required to do this

by Hugsbox

6/2/2026 at 2:15:51 PM

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

by antoine-codefly

6/2/2026 at 2:17:07 PM

Just wrapping up the beta for iOS! Will let you know asap.

by mrroryflint

6/2/2026 at 2:29:45 PM

What does native give you that this doesn't?

by tantalor

6/2/2026 at 1:48:21 PM

10 round avg 4.5%.

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

by zokier

6/2/2026 at 2:58:37 PM

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

by FinanceFreddy

6/2/2026 at 2:00:23 PM

10 perfect hits in a row!

...

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

by 0x000xca0xfe

6/2/2026 at 1:37:35 PM

800

0 out of 1,600

I still missed. Even when there was centered text.

Maybe the human is the weakest link

by ramon156

6/2/2026 at 11:27:09 AM

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

by ketul_shah

6/2/2026 at 3:53:18 PM

love it, pulls you in after a first try)

by oastp

6/2/2026 at 3:14:56 PM

Simple premise, oddly hard to put down.

by lbeyer

6/2/2026 at 3:27:31 PM

Really fun! I am pretty much blind

by ehsangazarr

6/2/2026 at 4:31:16 PM

i got a 0.00% after 3 tries!

by cdelsolar

6/2/2026 at 2:46:31 PM

this was fun

by tt_dev

6/2/2026 at 10:21:51 AM

this is fun!

by trickybusiness

6/2/2026 at 3:27:39 PM

pretty fun!

by ehsangazarr

6/2/2026 at 11:05:52 AM

i made 0.87%

by elliotJames548

6/2/2026 at 9:09:40 AM

my best is 0.08%

by nextma

6/2/2026 at 2:13:33 PM

my avg was around 2% not able to do more than that lol

by aspectop