Resources / Comparison
iBlink vs Slow Blink
We publish Slow Blink, so read this the way you would read any comparison written by one of the two products in it. What we can promise is that the facts about iBlink below come from iBlink's own site and its coverage in the eye-care trade press, that we have not tested it hands-on, and that we say plainly where it is the better choice.
The two apps are unusually close in concept. Both watch your face through the webcam, both compute how often you are blinking, both process the video on-device and discard it, and both nudge you only when your rate drops rather than on a fixed timer. That already puts them in a small category — most “eye strain” apps for Mac are schedulers that never look at you. The differences are platform, price, and what the reminder feels like at 4 PM on a bad day.
| iBlink | Slow Blink | |
|---|---|---|
| Platforms | macOS and Windows | macOS only (Apple Silicon) |
| Price | 7-day free trial, then $4.99/month or $29.99 lifetime (3 device activations) | Free on the Mac App Store. Optional cat characters $1.99–$2.99, one-time, no subscription |
| Account | Yes — license key and device info are sent for authentication | None. Nothing to sign up for |
| Video handling | Processed locally in real time and immediately discarded; video never leaves the device | Processed in memory frame by frame, never written to disk, never uploaded |
| Calibration | Calibration wizard that adapts to eye shape and lighting | Short calibration on first launch that learns your own open-eye baseline |
| How it reminds you | Subtle on-screen visual cues when your blink rate drops below a healthy level | A cat creeps in from the corner of the screen; you blink, it slips away |
| Extras | Optometrist endorsement; a partner program for eye-care professionals | Blink-interval statistics over time, 20-20-20 break timer, browser blink test with no install |
Where iBlink is the better choice
You are on Windows, or you move between a Mac and a PC. This is the clearest case and it is not close. Slow Blink is macOS-only, and no amount of feature comparison changes that. If your work machine runs Windows, iBlink is the one that exists for you.
You want three machines covered by one purchase. The $29.99 lifetime license includes three device activations, which is a sane deal for a desk, a laptop and a home machine.
You want an eye-care professional's name attached. iBlink runs a partner program for optometrists and features a practitioner endorsement. If that reassurance matters to you, it is a real difference — we have no such endorsement and are not going to imply one.
Where Slow Blink is the better choice
You do not want to pay, or to hold a license. Slow Blink is free on the Mac App Store. There is no trial that expires, no subscription and no account: nothing is sent anywhere, including license checks. The paid part is cosmetic — extra cat characters at $1.99 to $2.99, bought once — and the blink detection is not behind it.
You have tried reminders before and turned them all off. This is the part we actually designed for. A reminder is only useful for as long as you tolerate it, and a rectangle that says you should blink gets muted in about a week. A cat that wanders into the corner and leaves when you blink is harder to resent, which is a small trick, but it is the difference between an app you keep and an app you uninstall. Whether that is true for you is genuinely a matter of taste, and the trial-free download makes it cheap to find out.
You want to see your own numbers. Slow Blink charts your average interval between blinks over time. Watching that line sag every afternoon turns out to be a more persuasive argument for taking breaks than any article about tear film, including ours.
You want to check before installing anything. Our 30-second blink test runs the same kind of detection in a browser tab. If it turns out you blink perfectly well during focused work, you have just saved yourself both apps.
What neither of us can claim
Both apps sit on the same thin evidence base, and it is worth saying so on a page designed to make you choose one. Blink-prompting software has been through four small randomized trials, which found it reliably raises your blink rate and modestly improves symptom scores — but every one of those trials tested a reminder on a fixed schedule. Nobody has run a trial on a webcam app that detects when you have stopped. That is the shared premise of iBlink and Slow Blink, and its published evidence is currently zero. Neither of us is a medical device and neither of us treats dry eye.
Try the free one first
Slow Blink is free on the Mac App Store — no trial period, no account, no subscription. Or measure your blink rate in the browser before you install anything at all.
Download Slow Blink Take the blink testOther options
These two are not the whole field. On macOS, BlinkMore is free and open source, Blink: Eye Strain Reliever is a $0.99 one-time purchase, and BlinkEasy covers both macOS and Windows — our comparison of 14 Mac eye-break apps lists what each one does and what it costs, including the timer-based apps if that turns out to be what you want.
Sources
iBlink details from iblink.ca and Glance by Eyes On Eyecare, 23 July 2026, both read on 24 August 2026. Pricing and features change; check their site before buying. Slow Blink details are our own.
We publish Slow Blink and have not tested iBlink hands-on; everything stated about it comes from its published material. This page is not medical advice, and neither app is a medical device. If you have persistent eye discomfort, please see an eye-care professional.