Sliding contact lenses can affect the comfort of wearing and the stability of the visual field, and may also cause other diseases. There are many reasons for the sudden slippage of contact lenses, let's take a look at them one by one.
Because the contact lens has to be close to the eyeball, it has a certain curvature, but the curvature of the two sides of the lens is not exactly the same. When the front is facing up, the edge of the lens is rounded and folded inward, which can fit well with the eyeball. However, with the reverse side up, the edge of the lens flips out like the edge of a small saucer. Therefore, if the lens is worn upside down, the fit is not good, and the positioning will be unstable, which will lead to the problem of sliding.
If the base arc of the lens is much larger than the base arc of the eyeball, it can also cause slippage. When the eyeball is rotated rapidly, the lens with too large base arc always lags and shifts, and cannot be closely attached to the eyeball. Vigorous movement may also cause the lens to slip. Generally speaking, the contact lenses on the market can fit the base arc of most people, and only a few people have a special base arc, which may cause the problem of sliding.
Under normal circumstances, when there is a problem of slippage and foreign body sensation, you should immediately remove the lens for cleaning, and then re-check the front and back before trying to wear it. If there is still a slippery lens after repeated attempts, it is the inappropriate selection of the base arc. It is recommended that you re-measure and purchase contact lenses with more matching base arcs.
In fact, poor lens quality and poor molding can also cause slippage. The editor still recommends that you fit contact lenses in formal places, especially for novice wearers, which can effectively avoid problems such as slippage or other discomfort.