Due to space constraints in print, our product reviews are often shorter than some pieces of kit that we test deserve. We therefore occasionally publish longer, in-depth reviews on our website.

We’re super impressed with these goggles with a built-in head-up display that shows you live metrics as you swim. For pool training, they’re a game changer. I’ve been using these now for about six weeks and I’m already hooked on the continuous feedback they provide.

From the moment my FORM Goggles arrived, I felt I was dealing with a high-quality piece of kit. The goggles are nicely packaged and come with a robust case to encourage you to protect and keep them in top condition between swims. Ignoring the fancy electronics for a moment, these goggles are built to last. The seals are comfortable and the choice of five nose-piece sizes means they should fit anyone. Vision is clear and I’ve had no issues with the lenses fogging up while swimming, even after multiple sessions.

Due to the electronic wizardry fitted to the side of one of the eye-pieces, there’s no way to avoid these goggles being slightly heavier than a regular pair. While swimming, if you focus on it, you can just about feel the black box on the side but, quite honestly, you quickly stop noticing it’s there.

To make full use of the goggles, you’ll need to download the FORM app to your phone and pair your phone with the goggles via Bluetooth. This sounded like it would be complicated but turned out to be straightforward. The app interface is intuitive and easy to use. After creating an account, the first thing to do is choose what you want to see when you are swimming. There’s a long list of metrics to choose from including split time, stroke rate, stroke count, pace, length count, total distance etc.

At this point, you start to appreciate how clever the electronics in these goggles are, and how well they’ve been designed to meet the needs of serious swimmers. There are two swimming modes to choose from: Lap Swim or Intervals. The latter is what you want if you’re doing any kind of structured training session. The Lap Swim mode is aimed at swimmers doing continuous swims who primarily want a record of time and distance. In both modes, there are three different display types: while swimming, after a turn and while resting. Let’s look at each of these.

The goggles automatically detect when you push off the wall and start swimming (unlike most swimming watches that require you to press a button to start the timer). In Intervals mode, the top part of the screen is fixed to show your current interval time. You can select what to see in the bottom half of the screen. I usually opt for pace per 100m for the current interval. In Lap Swim mode, the top half of the screen displays your total swim time and you can choose metrics such as your previous length pace or total workout distance to show in the bottom. For the record, I’ve only used the Lap Swim mode once as I found the Interval mode much more useful for the type of swimming I do.

At every turn, the goggles detect the change of direction, and for a few seconds you’re shown the “Turn Screen”. This still has the interval time in the top half (or total time in Lap mode) and you can choose what shows up in the bottom with lots of useful options such as your stroke count for the previous length or (for those of us who have trouble counting above three) your number of lengths for the interval.

Then, at the end of your interval, you’re shown the “Rest Screen”. Again, there is no need to press any buttons to say you’ve finished an interval. FORM detects that automatically. Here you have a choice what to display in the top half of the screen between the total time for the interval or how long you’ve been resting. The bottom half rotates between three different pieces of information that you can choose. I like to see my time for the last interval, my pace for the interval and the total distance I’ve completed in the session – but there are many more options.

At the end of your swim, press stop, and then, while you’re changing, you can download all the data from your session to your phone for a full record of what you’ve done. There’s also some clever stuff going on in the app that detects when you’ve done a set and groups intervals together accordingly. There are also options for sharing your data and following other swimmers. All good stuff.

Another thing worth noting is that the goggles automatically detect what stroke you are swimming and this is recorded in the final data. The only time you might want to press any buttons mid session would be if you wanted to do drills or kicks as there’s an option to set the goggles into drills mode. I have to confess, I haven’t used this!

Over the six weeks that I’ve been using these goggles, they’ve been almost 100% accurate in recording time, strokes and distance. The only times they’ve got it wrong are when I’ve jumped out of the pool for a dive start (they recorded the motion of getting out of the pool as starting a length) or when I’ve paused mid-length to let a faster swimmer overtake.

Don’t worry if you don’t swim in a standard length pool. There are default settings for 25y, 25m and 50m but it only takes a few seconds to set a custom length. One slight niggle for me is that I swim in a 33 1/3m pool, which I have to set as 33.3m. A 100m swim is then recorded as 99.9m. This is something that FORM will hopefully fix in the near future.

A quick word about the display. I think it’s green, but other people tell me it’s yellow. Aside from that, it’s completely clear and in focus, even though I’m short-sighted (prescription -2.5). I’ve also shown the goggles to people who are long sighted, and they can also see the display clearly. It’s very clever. It is a slight distraction while swimming and I missed a couple of turns when first wearing the goggles but you soon adjust and learn to switch your focus quickly between the display and your environment.

Finally, these goggles are meant for pool use, not open water. The only useful data they could show you at the moment would be total time and possibly stroke rate. We hope one day there’ll be a GPS enabled version for outdoor use. Meanwhile (although we haven’t tested it) from November 2019, FORM will support Polar’s OH1 and OH1+ optical heart rate monitors, allowing you to view your heart rate as you swim.

Oh, and the battery life is excellent. I can easily do five or six swim sessions between charging.

See our interview with FORM Swim founder and CEO Dan Eisenhardt