Place the lens on the tip of your index finger.
Hold it under a light source to help you see better.
Check the edge of your lens.
If the edges flare out, it's inside out. Your lens should look like a bowl with straight edges.
Look out for the ‘1,2,3’ indicator.
Except for DEFINE® and ACUVUE® Astigmatism lenses, look out for the 1, 2, 3 indicator. If you can read the numbers in order, your lens is flipped correctly.