Soft contact lenses are designed to be thin, flexible, and comfortable, but their pliable nature makes it easy to accidentally insert them inside out. This common mistake occurs because the lens has a precise curvature that must align perfectly with the eye’s surface for optimal vision and fit. When the lens is reversed, this curvature is inverted, preventing the lens from settling correctly on the cornea. The resulting disrupted fit immediately alerts the wearer that something is wrong.
Identifying a Misoriented Lens
Before a reversed lens ever touches the eye, there are practical ways to check its orientation using simple visual inspection. One reliable method is the “taco test,” which involves placing the lens on your index finger. When correctly oriented, it forms a smooth, perfect bowl shape with edges pointing straight up, much like a hard-shell taco.
If the lens is inside out, the edges will flare slightly outward, creating a shape more akin to a rimmed soup bowl or a saucer. Many manufacturers also embed tiny laser markings, such as the numbers “123” or a specific letter, near the edge of the lens to assist with this check. When viewed correctly, these markings will read normally, but if the lens is reversed, the numbers or letters will appear backward.
Immediate Discomfort and Visual Changes
The most immediate and noticeable consequence of wearing a misoriented lens is physical discomfort within the eye. This sensation is often described as generalized scratchiness, grittiness, or the feeling of a foreign object being lodged beneath the eyelid. This irritation occurs because the reversed, flared edge of the lens rubs against the delicate tissues of the conjunctiva and the inner eyelid with every blink.
The lens will not adhere properly to the cornea and will likely move excessively upon blinking or looking around. A backward lens often feels loose, may slide off the center of the eye easily, or can even pop out without warning. While vision may not always be severely blurred, the improper fit can sometimes lead to slight distortion, especially around the edges of the visual field. This poor fit disrupts the precise optical alignment needed for clear sight and can lead to excessive tear production as the eye attempts to flush out the irritant.
Safe Correction and Next Steps
If you suspect or confirm that a lens is inside out, the first step is to remove it immediately to prevent prolonged irritation. Before touching the eye or the lens, it is important to thoroughly wash your hands with soap and water and dry them with a lint-free towel to minimize the risk of introducing contaminants. Gently remove the lens from the eye and place it in the palm of your hand.
Rinse the lens with fresh, sterile contact lens solution, making sure never to use tap water, as it can harbor microorganisms harmful to the eye. After rinsing, re-examine the lens using the visual inspection methods to ensure the edges are correctly curved inward. Once the lens is verified as being the right way out, you can safely reinsert it into the eye.
If discomfort or redness does not resolve quickly after reinsertion, or if you experience persistent pain, light sensitivity, or a lingering foreign body sensation, remove the lens entirely. These symptoms may indicate a minor corneal abrasion, and you should seek advice from an eye care professional immediately.