There are two different types of lines under the eyes. Those that are there at rest and those that come about from animation (smiling in your case). The lines that are there at rest can be alleviated with some form of resurfacing procedure or possibly by placing a filler such as Restylane deep to the muscle with the result being a plumping of the area. With young women that have those lines at rest, I have found great success with medium chemical peels.If the lines are occurring mostly with animation, then Botox can be performed, but remember that it is an off label use and could potentially take away from the utility of the muscle, which is to protect the eye, maintain the lower eyelid position, and help with the control of the tear blanket. I do not agree that an injeciton of botox will cause any kind of atrophy, as this is a temporary product that does not affect the muscle itself, but rather the neuromuscular junctions.You have a couple of options. I recommend that you speak with a Board Certified Facial Plastic Surgeon.Good Luck