Soft contact lenses are incredibly thin and flexible, which means they can easily flip inside out during handling, making insertion a challenge. Placing a misaligned lens onto the eye is a common mistake that can lead to immediate discomfort and irritation. Determining the correct orientation is a simple process that only requires a few seconds of inspection before the lens is placed on the eye. Identifying the misalignment before insertion ensures the lens fits properly over the cornea for optimal vision.
Three Quick Tests to Check Orientation
The easiest way to check a soft contact lens is the side-view method, which involves placing the lens on the tip of your index finger. When held up to eye level, a correctly oriented lens forms a smooth, perfect cup shape, with the edges curving straight upward. If the lens is inside out, the edges will flare outward, creating a shape that looks more like a rimmed bowl or saucer. This difference indicates that the lens curvature is inverted and will not conform correctly to the eye’s surface.
A second technique is often called the “taco test” because of the resulting shape. To perform this, place the lens between your thumb and forefinger and gently squeeze the sides together as if folding it in half. If the lens is right side out, the edges will naturally roll inward, forming a clean, semi-circular shape like a hard-shell taco. Conversely, a backwards lens will resist this smooth fold, and its edges will bend or flare outward.
Many manufacturers incorporate microscopic laser etchings to assist wearers in verifying the lens orientation. These markings are typically a series of numbers, such as “123,” or small letters placed near the outer edge. To check for this, place the lens on your fingertip and hold it up to a bright light source. If the lens is correctly positioned, the numbers or letters will appear right-reading; if the lens is inside out, the markings will be reversed.
Signs You Are Already Wearing a Backwards Lens
If a lens is accidentally inserted inside out, the wearer will usually experience an immediate sensation of foreign body irritation or grittiness. This discomfort occurs because the slightly flared edge of the inverted lens is not sitting flush against the eye’s surface. A correctly fitted lens should feel nearly unnoticeable, but an inverted one will constantly remind the wearer of its presence.
Another common symptom of a backwards lens is excessive movement, where the lens shifts noticeably with each blink. The inverted curvature prevents the lens from adhering properly to the cornea, causing it to slip or even pop out unexpectedly. This instability results from the improper base curve not matching the natural curvature of the eye.
Visual symptoms can indicate a misalignment, often presenting as blurry or fluctuating vision that does not clear up with blinking. While the lens is still providing vision correction, the incorrect fit distorts the optical surface, leading to uneven clarity. The eye may become noticeably red or watery as it attempts to flush out the source of the persistent irritation.
Proper Insertion and Troubleshooting
If you suspect a lens is inside out after insertion, remove it immediately to prevent further irritation. Always wash your hands thoroughly with soap and water before touching your eye or the lens, as this minimizes the transfer of contaminants. Once removed, the lens must be rinsed with fresh, sterile contact lens solution; never use tap water, which can harbor harmful microorganisms.
After cleaning, re-examine the lens using one of the quick orientation tests to confirm it is forming the correct cup shape. If the lens appears damaged or if the irritation persists even after a correct re-insertion, the lens should be discarded. Should eye redness, pain, or blurred vision continue for more than a few hours, contact an eye care professional for an immediate examination.