Check whether the contact lens feels uncomfortable, scratchy, or keeps moving around
Look at the lens shape on your fingertip; it should look like a smooth bowl, not a flared saucer
If the edges flare outward, the lens is likely backwards
If the edges stand straight up and form a rounded cup, the lens is likely correct
Place the lens on your fingertip and view it from the side
If the rim curves outward, it is likely inside out
If the lens feels right but vision is blurry, remove it and check the orientation
Some lenses have markings or numbers that should read correctly when the lens is right side out
If the lens tears or folds easily when inserted, it may be backwards
If the lens feels better after flipping it, it was likely inside out