Ortho k lenses are a special kind of hard contact lens worn at night to reduce, eliminate or prevent myopia.
They are smaller and more rigid than conventional soft contact lenses. They are highly specialised in their design, using ‘reverse geometry’ principles to gently mould the central portion of the cornea into a slightly flatter shape during sleep.
How do ortho k lenses work?
For people who are short-sighted, the cornea is like a camera lens that is too curved (convex) in shape. This means that it does not focus light correctly. Changing the shape of the lens by making it less curved makes it focus light properly, thus giving the eye clear vision.
Ortho k lenses are manufactured with ‘breathable’ plastic materials that allow a good amount of oxygen to pass through them and keep the cornea healthy. They are also designed to give great vision whilst they are being worn – if you wake up during the middle of the night, you should be able to see perfectly.
How do I care for my ortho k lenses?
The lenses need to be cleaned every day with purpose-made cleaning solutions to ensure that they are as clean and disinfected as possible before being worn in the eye.
Even when you are successfully wearing these lenses, you should have regular check ups with your optometrist – at least every 6 months.
A single pair of ortho k lenses that are well looked after can last up to 1.5 to 2 years before they need to be replaced.