Inside Out Contact Lenses

by admin on March 2, 2011

Is your contact lens inside out? How can you tell? This is a question many new and experienced contact lens wearers have. Initial contact lens designs were thicker and wearers placed the lens on the end of their index finger to see if it was curving correctly. If the lens was correct, it would have a “bowl” shape, if the lens was inside out the ends would turn out slightly.

The “Right” lens forms a “U” shape and is in the correct position. The “Wrong” lens forms a “U” but the top edges flare out, so it’s inside out.

Today, in light of manufacturer’s trying to improve lens design and enhancing comfort, it has become a lot harder to figure out if your lens is inverted or not. To help with this, contact lens companies have developed and now use inversion indicators or inversion markers on soft lenses to make it easier to put your lens in the correct way.

The inversion marker can be anything from a laser marking, such as the brand name to numbers or a series of letters on the edge to help you discover which side should be up or down. If you can read it properly when holding your lens on the end of your finger, the lens is correct.

Here is an example of one manufacturer using the marker, “OK.” On the first lens you can read “OK” clockwise around the edges of the lens, this is correct. The second lens has “OK” backwards on the edges, and “OK” can be read counter clockwise, which means the lens is inside out.

If you feel you need more help with your lenses here is a video that shows you how to tell if your lenses are inside out:


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{ 1 comment… read it below or add one }

frankgilliano777@gmail.com' Frank Gilliano September 30, 2011 at 8:49 am

Interesting. I always wondered how you can tell, although now my optometrist says my current lenses can’t be inside-out.

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