Not having much on top, I always use a hat if there is any chance of burning but I really don’t like running in a hat if I can help it. Having said that, I don’t like sweat in my eyes.
I’ve heard of runners using Vaso on their forehead to stop sweat in the eyes. Anyone done it? Does it work?
never heard of it… can just imagine a carpet of bugs stuck to your forehead after a few miles! 
Could try some sort of sweatband under your cap?
Sweaty much?! Surely that’s gonna clog up all your sweat glands … and i can’t see that being a good thing in the slightest! This is a mad idea 
I have been known to deploy a buff on many an occasion; although generally not for full head coverage; I generally go for the well-dodge headband look 
As an aside, Vaseline is no good at blocking the sun; I have found that out before. @FatPom could just grow really bushy eyebrows; isn’t that what they’re for! Don’t forget to post a pic 
… and didn’t you live in Oz for years @FatPom?! We should be coming to you for heat/sun tolerance advice!!!
I obviously didn’t put this very well. That Vaso isn’t for sun protection, I use a hat/buff or anything else for that.
What I was getting at, is on days when you don’t need a hat for the sun because it’s cold, I’ve heard of runners smearing a strip of Vaso on their forehead to divert the sweat away from their eyes.
I don’t even know where I read it. Perhaps I imagined it?
ETA: actually I can see the confusion now. i only typed about half of the words that were in my head in the OP. I blame work (or Wiggle).
Is this not what eyebrows were invented for?
I have heard of this practice, but probably from the 80s before people wore caps or buffs. I know what you mean though, and I usually just end-up constantly wiping my bicep against my brow.
One thing I can’t recommend is putting sunscreen on your forehead before going for a surf. Don’t ask me how I know.
Don’t use it anymore, but I have dabbled with vaseline above the eyebrows, works well in that it diverts the sweat wherever you want it to go, however the vaseline is modelled.
Think it worked well in that 30-40 degree Etape Due Tour in 2007, but in Blightly, hmmmmm, don’t think I’ve ever used the technique here.
Never needed it cycling, as I always use a bandana or light skull cap.
Yup headband buff is a strong look. I always use it on the turbo & often when running in the hills when you transition from running up - pouring with sweat - to running downhill & needing full ocular function.
am amazed no one has suggested a visor yet?
I’m the plonker who even runs in one at night to stop sweat dripping onto my glasses (when appropriate, I hasten to add this is not a frequent occurrence )
If it’s cold buff as a headband. If it’s warm, then buff as a wristband mop. And i’m a sweaty bu**er
A swipe of Vaseline on the eyebrows works.
Not a swathe across the head 
Ah yes; the Postie is used to dropping stuff in the garage when I’m on my trainer in bib shorts & headband the strongest of strong looks
Gawd, I’ve had that a couple of times on the turbo. Bibs on, and just a base layer, doorbell rings and I answer. they can’t see the bike, just a sweaty fat guy in dodgy clothes.
I ask them if they need a signature and they usually back away quickly saying ‘that’s ok’. 
I was happily lunchtime turbo-ing at work once when some tw@t decided a fire drill would be necessary. I looked a fine sight at the muster point 
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