HycoSan Shield is the water-free "oil" drop I use to stop my tears evaporating so fast. It's the same thing as EvoTears, and the same drug as the US prescription drop Miebo, except here we can just buy it. Here's honestly what it's like, the trick to using the bottle, and when it helps me most.
I first tried HycoSan Shield because I'd been reading about Miebo in the US, this new prescription drop everyone was talking about. And here's a lucky one for us: in England, we don't have to get it on prescription at all. We can just buy it on Amazon. This is the thing about dry eye treatments, they genuinely vary from country to country, and this is one of the times we're lucky to be able to just pick it up over the counter.
I like to try and keep up to date with the newest drops and treatments, so I gave them a go. I first tried them during a flare-up, because if you've ever been in a dry eye flare, you know the feeling, and you'll try anything and everything to get out of it.
Yes, and this is worth knowing, because it's sold under a confusing number of names. HycoSan Shield, EvoTears and NovaTears are all the same drop: 100% perfluorohexyloctane, a water-free, preservative-free liquid that replaces the oily part of your tears. In the US, the same active ingredient is the prescription drop Miebo. So if you've been reading American articles about Miebo or EvoTears, they're describing exactly what I use, and in the UK you can simply buy HycoSan Shield off the shelf. The bottles differ from brand to brand, but the drop inside is the same.
It's aimed at people like me, with the oil side of dry eye: meibomian gland dysfunction and evaporative dry eye. Your oils are what keep your tears sitting on your eyes. If you don't have enough of them, your tears evaporate far too quickly. This drop forms a thin protective layer that slows that evaporation right down. It really does what the name says: it's a shield between your eyes and the rest of the world.
Here's the bit I wish I'd known first. Because I didn't read my leaflet (who does?), I got it wrong at the start. I was just squeezing it like a normal drop, getting far more than one drop out, and ending up with it running down my face, which is not what you want when it's twenty pounds a bottle.
My mum was the one who spotted I was doing it wrong. Here's the proper way:
Once you've got the knack it's easy, but it genuinely is worth learning, because the technique is the difference between one neat drop and half the bottle running down your cheek.
They do feel a bit bizarre at first, because they're oil-based rather than water-based. You get that same odd sensation I get with the oil-based prescription drops: it's hard to tell the drop has actually gone in, unlike a normal watery drop where you feel it straight away. It's a strange feeling, just different, but honestly not unpleasant. For me it took maybe a couple of weeks before I stopped noticing it in my eye at all. I know some people don't love the feeling, so I'd say give it a little while before you decide.
This is the tip that made the real difference for me, and I read it online. You put a normal lubricating drop in first (I use HycoSan Extra), wait about a minute for it to be absorbed, and then you put the HycoSan Shield on top. It locks that first drop in place.
Someone online described it as the cling film around your sandwich, and I think that's a brilliant little analogy. Your lubricating drop is the sandwich, and the shield goes over the top to seal it and stop it drying out. It's exactly how they work.
Here's where I think a lot of people go wrong, and why some say it "doesn't work". HycoSan Shield is not a rewetting drop, and it isn't meant to be used like one. A normal preservative-free lubricating drop (like HycoSan Extra) you can put in as often as you like, a hundred times a day if you want. Don't do that with these.
Its job isn't to lubricate or rewet your eye. Its job is to replace the oily layer that stops your tears evaporating. So if you swap your usual lubricating drops out for this and use it on its own, your eyes aren't actually being lubricated, and you'll think it's failed. That, I'm fairly sure, is the mix-up. It's a shield to go on top of your normal drops, not a replacement for them.
So two rules I'd give anyone starting out: always put a lubricating drop in first, and use HycoSan Shield up to about four times a day, no more. It's a tiny, pricey bottle, and with these, more isn't better, that's simply not how they work.
I'll be honest: I like these, and I find them genuinely beneficial. They keep my other drops working in my eyes for longer, which means I'm reaching for drops less often through the day. That's a real win when your day can otherwise revolve around reapplying.
I try to use them first thing in the morning: a lubricating drop, then the shield on top, to keep my eyes fresh through the day. I also reach for them during flare-ups, and I always take them on planes, because a plane is such a harsh, drying environment that you want to protect your eyes as much as possible, and locking in that first drop really does help.
Honest confession: I should use them more consistently than I do. My goal is to get a proper system going with my drops, so I'm putting the shield in at least every morning rather than only when things get bad. If you're more disciplined than me, I suspect you'd get even more out of them.
They come in a small bottle that costs around £19.90 on Amazon UK. So they're not the cheapest, which is exactly why it's worth learning the bottle technique so you're not wasting half of it (like I was at the start). The good news is they're very easy to get hold of over the counter, no prescription, no faff, if you want to try them.
If your dry eye is on the evaporative / oil side, like mine, HycoSan Shield is genuinely worth a go, especially as you can just buy it off Amazon without a prescription. It's not a cure, nothing is, but it keeps moisture on my eyes for longer and cuts down how often I reach for drops, and that makes a real difference to a day. My honest advice: give it at least four weeks so you get used to the feel and can properly judge whether it helps you, always put a lubricating drop in first, and don't expect it to rewet your eyes, because that isn't its job.
Is HycoSan Shield the same as EvoTears and Miebo?
Yes. HycoSan Shield, EvoTears and NovaTears are the same drop (100% perfluorohexyloctane), just different brand names. In the US the same active ingredient is the prescription drop Miebo. So American reviews of Miebo or EvoTears are describing the same thing I use, which in the UK you can simply buy over the counter.
What is HycoSan Shield used for?
It's aimed at evaporative dry eye and meibomian gland dysfunction, where the problem is the oily (lipid) layer of your tears. Your oils keep your tears on your eyes; without enough of them, your tears evaporate too quickly. HycoSan Shield forms a thin protective layer that slows that evaporation, like a shield between your eyes and the air.
How do you use the HycoSan Shield bottle?
It caught me out at first (I wasted a fair bit down my face). The proper method: hold the bottle upright and lightly squeeze, then keep it squeezed as you turn it upside down over your eye and release, which draws air in, then squeeze once to release a single drop into your lower eyelid pocket. Learning that is the difference between one neat drop and wasting half the bottle.
How often should you use HycoSan Shield?
Up to about four times a day, and no more. It's not a rewetting drop you can use as often as you like (that's what a lubricating drop like HycoSan Extra is for). Always put a lubricating drop in first, then the shield on top. It's a tiny, pricey bottle, and more isn't better.
Why isn't HycoSan Shield working for me?
The commonest mistake is using it instead of your normal lubricating drops. It doesn't rewet or lubricate your eye; its job is to replace the oily layer that stops your tears evaporating. If you swap your lubricating drops out for it, your eyes aren't being lubricated and it'll feel like it's failed. Use it on top of a lubricating drop, not instead of one, and give it at least four weeks.
Does HycoSan Shield sting or feel strange?
It doesn't sting. Because it's oil-based rather than water-based, it feels a bit different and it can be hard to tell the drop has gone in, which takes some getting used to. For me it was maybe a couple of weeks before I stopped noticing the feeling. It's not unpleasant, just different.
Can you use HycoSan Shield with other eye drops?
Yes, and layering is where it works best. Put a normal lubricating drop in first (I use HycoSan Extra), wait about a minute for it to absorb, then put the HycoSan Shield on top. It locks that first drop in, like cling film around a sandwich, so your eyes stay comfortable for longer and you reapply less.
How much does HycoSan Shield cost, and where can you buy it?
It's around £19.90 for a small bottle, and you can buy it easily over the counter on Amazon UK, no prescription needed. Because it's not cheap, it really is worth learning the bottle technique so you're not wasting drops down your face like I was at first.
More of my journey: Flying with dry eye → · My LipiFlow experience → · How I got diagnosed →