neutralisation

Neutralisation is the step in the care process whereby hydrogen peroxide in lens solution is broken down into water and oxygen. Hydrogen peroxide is a powerful disinfectant used to clean and disinfect contact lenses, but it is too harsh to come into direct contact with your eyes. That is why it must be completely neutralised after disinfection.

The neutralisation process occurs through a chemical reaction involving a catalyst, usually a platinum tablet or disc. This catalyst is housed in the lens case of the peroxide system and ensures that the hydrogen peroxide is converted into harmless substances within a few hours. Without this neutralisation, the solution would feel burning and painful in your eyes.

Most peroxide systems require a neutralisation time of at least six hours. Some systems use a tablet that you add yourself, whilst others have a built-in platinum disc in the lens case. It is important that you observe the minimum waiting time, as otherwise the solution will not yet be fully neutralised.

Once neutralisation is complete, the liquid has effectively become a salt solution, similar to saline. Your lenses are then safe to wear. Neutralisation takes place automatically whilst your lenses are being stored; you do not need to do anything yourself apart from leaving the lenses in the case for long enough.

How does neutralisation work in practice?

If you use hydrogen peroxide solution, place your lenses in the lens case in the evening and fill it with the solution. Disinfection begins immediately, and at the same time, the neutralisation process is triggered by the catalyst in the case. After at least six hours, the process is complete and your lenses are safe to wear. It is important that you never remove your lenses from the case before this time, not even to rinse them briefly.

Some systems indicate that neutralisation is taking place through a colour change or a fizzing reaction. This is normal and means that the catalyst is working. Always use the lens case that comes with the system, as only that contains the correct catalyst for that specific solution.

Why neutralisation is necessary

Hydrogen peroxide is effective at disinfecting lenses, but it must not come into direct contact with your eye. Without neutralisation, it would cause a burning sensation, redness and watering. The neutralisation step makes the system safe and comfortable, whilst still allowing you to benefit from the thorough cleaning provided by peroxide.

Peroxide systems are particularly suitable if you are sensitive to preservatives in all-in-one solutions, as the solution no longer contains any preservatives once it has been neutralised. Neutralisation ensures that you are left with a preservative-free solution.

Peroxide solutions at SMEYEL

At SMEYEL , you’ll find various peroxide solutions with matching lens cases and neutralisation systems. Each system has its own neutralisation method, so always follow the instructions for the product you’re using.