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“Spectacle Blur”
After Wearing Contacts Lenses

“Why can’t I see well with my classes after taking out my contact lenses?”  A person who wears contact lenses should be able to switch to their eyeglasses at any time and expect to see just as well. Some people experience blurred vision when they exchange their contacts for eyeglasses. This blurring may be mild to severe and can last from a few minutes to many hours, or even for days or weeks; however, it is almost never permanent.

When you wear your contacts all during your waking hours and never put on your eyeglasses, you could have the problem and not even be aware of it. But if you frequently alternate between your contact lenses and eyeglasses for your work, the blur can be very annoying.

Either way, extended “spectacle blur” is not normal. While a few moments of blurred vision is acceptable, a long period is not, and indicates that your corneas could be getting harmed by your contact lenses.

What Causes the Blurred Vision?

The main cause of spectacle blur is that the contact lens slightly “warps: the cornea (the eye’s clear focusing surface on which the contact lens floats). Normally after the contact lens is removed, the cornea quickly returns to its proper shape. There are two main contributors to corneal warping: poor-fitting contact lenses and poor oxygenation of the corneas.

Contact lenses, especially the rigid types of lenses, must fit properly on the cornea. If the lens fit is poor, it can indent the corneal surface and change its shape. But even well-fitted lenses can cause some warping by interfering with the amount of oxygen that feeds the cornea. Soft and oxygen-permeable lens materials minimize this problem, but no type of lens can offer 100% of the air to reach the cornea. In addition, everyone’s corneas are different and some require more oxygen that can pass through any type of lens.

If the cornea does warp, you are not likely to notice the blurring while wearing the contacts because there is a layer of tears between the lens and the eye. The tear fluid fills in the defect and optically corrects for it. Only when the contacts are removed will you be able to notice a disturbance in vision that your eyeglasses can not correct. There’s no need to fear that wearing contact lenses might lead to keratoconus (cone-shaped corneas). Keratoconus is hereditary and is not related to the warping caused by contact lenses.

How do the Different Kinds of Contacts Affect Spectacle Blur?

Any kind of contact lens material can cause spectacle blur, but rigid lenses (PMMA) are the culprit more often than any other type of contact lens.  Spectacle blur is one reason many hard contact lens wearers have had to stop wearing even well-fitted lenses; however, if you are wearing rigid lenses and they’re comfortable and give you good vision, you can continue to do so. Always remember that you need to maintain a schedule of regular eye checkups. Soft, semi soft, gas permeable, and extended wear contacts all cause less spectacle blur because they are made of combinations of plastics that “breathe”, allowing some oxygen from the air to pass through tiny pores in the lenses.

What Should be Done Now?

If you’re troubled by significant spectacle blurs, something is wrong that may need prompt attention. The fit of your contacts should be checked and if refitting is necessary, you may have to stop wearing any contacts at all until your corneas return to their normal shape. This could take at least a week. If the problem is not in the fit, you may need to change to a type of contact lens that allows more oxygen to reach the cornea.

If your vision is so blurred with your present glasses that you can’t use them, it may indicate serious warping that could take even months to undo. To see clearly while you’re waiting, you may need a new pair of glasses. You may even need to have a prescription changed more than once, as the cornea slowly resumes its natural contour. During this period your corneas will be checked at regular intervals until they become stable.

If there appears to be any chance of permanent corneal damage, you may have to stop wearing contacts altogether. While such a drastic step is rarely necessary the safety of your eyes is always the guiding principle.