Place the lens on your fingertip and look at the side profile
If the edges flare outward like a saucer, the lens is inside out
If the edges point straight up like a bowl, the lens is correct
Hold the lens up to the light and check for a smooth, even rim
If the rim looks uneven or flared, the lens is inside out
Check for any laser markings or indicators, if your lens has them
If the lens feels uncomfortable or blurry after insertion, it may be inside out