Silicone hydrogel: the oxygen upgrade
It's the one material number worth caring about. Here's what silicone hydrogel is, why it lets far more oxygen reach your eye, and who actually benefits from it.
Soft contact lenses are made from one of two material families: regular hydrogel or silicone hydrogel. They look the same in your hand — the difference is how much oxygen they let through to your cornea.
Hydrogel vs silicone hydrogel
A hydrogel lens is water-based — oxygen reaches your eye only by dissolving through the water in the lens. To get more oxygen, you need more water, and there's a limit before the lens gets too fragile or dries out.
A silicone hydrogel lens adds silicone, which is highly oxygen-permeable on its own. Oxygen passes through the silicone directly, so the lens can deliver far more oxygen without relying on high water content. That's why it's considered the modern upgrade.
| Silicone hydrogele.g. S-Series | Regular hydrogele.g. A / M-Series | |
|---|---|---|
| Oxygen to the eye | Very high | Moderate |
| How oxygen passes | Through silicone directly | Through water only |
| Typical Dk/t | 100–190+ | ~20–40 |
| Best for | Long / all-day wear | Comfort & everyday value |
| moodyPlus example | S · moody+Silicone (187 Dk/t) | A & M series |
Dk/t = oxygen transmissibility through the lens. Higher means more oxygen reaches the cornea. Values are typical ranges, not a fitting recommendation.
What “Dk/t” actually means
Dk/t is the single number that describes how much oxygen gets through a lens to your eye. Dk is the material's oxygen permeability; t is the lens thickness. Divide one by the other and you get how much oxygen actually reaches the cornea at a given thickness — so a higher Dk/t is better.
Our S-Series runs at 187 Dk/t — among the highest available, and the reason it's built for long screen days.
Why more oxygen matters
Whiter, fresher eyes
Corneas that breathe are less prone to the redness that comes from oxygen starvation.
Comfortable longer wear
More oxygen supports all-day and long-screen wear with less end-of-day fatigue.
Less dependence on water
Oxygen doesn't rely on high water content, so lenses can stay comfortable without drying as fast.
Is silicone hydrogel for you?
- ✓Long screen days, all-day wear, or eyes that redden by evening → yes, go S-Series
- ~Occasional wear, sensitive eyes, or value-first → a hydrogel daily (A or M) may suit you better
Common questions
Which moodyPlus lens is silicone hydrogel?+
Is higher water content the same as more oxygen?+
Do I need silicone hydrogel if I only wear lenses sometimes?+
Want the oxygen upgrade?
The S-Series is our silicone hydrogel lens — pick daily or monthly and your Diopter.