A Breakthrough for Evaporative Dry Eye
Perfluorohexyloctane (often called PFHO) is a next-generation treatment used for evaporative dry eye disease, especially when meibomian gland dysfunction (MGD) is the underlying cause. It belongs to a class of molecules called semifluorinated alkanes, which behave very differently from traditional artificial tears.
How It Works
Instead of simply adding moisture, PFHO works by:
- Spreading evenly across the tear film
- Forming a lightweight, protective layer on the eye’s surface
- Preventing the tears from evaporating too quickly
This makes it particularly effective for patients whose dry eye stems from poor oil production or unstable tear films.
Why It’s Different
PFHO isn’t an artificial tear—it’s a water-free solution with some unique advantages:
- One drop lasts hours, rather than minutes
- No preservatives
- Doesn’t blur vision the way thicker lubricants can
- Restores the lipid layer, which is the root issue for many dry eye sufferers
Patients often notice a smoother, less gritty feeling and improved comfort with screen use or in dry environments.
What Conditions It Helps
PFHO is most commonly used for:
- Evaporative dry eye
- Meibomian gland dysfunction
- Tear film instability
Safety and Side Effects
PFHO is generally well-tolerated. Some patients notice mild, brief blurred vision or a lightweight sensation right after instilling the drop, but this typically resolves quickly. Because it’s preservative-free, it’s safer for long-term use.
**Is PFHO a “Forever Chemical”?
Why the Answer Is No**
👉 PFHO is fluorinated, but not a “forever chemical” in the harmful PFAS sense.
👉 It does not enter your bloodstream or organs.
👉 It does not persist or accumulate.
👉 Current data strongly supports its long-term safety when used on the ocular surface.
What we know
- In Europe, the molecule Perfluorohexyloctane (PFHO) is available over-the-counter (OTC)
- Products branded EvoTears and Hycosan Shield (which contain 100% perfluorohexyloctane) are marketed in Europe.
- The molecule has been CE-certified and rolled out in Europe since ~2015 under various brand names.
- Although available OTC in Europe, in other markets (like the US) it is prescription-only. For example, under the brand Miebo in the US it’s Rx-only.