Your individual needs will determine the number of BOTOX units needed to treat the specified area. To determine your needs, it's best to have a consultation with a qualified health professional at Medical Rejuvenation Clinic.
Generally, men require more BOTOX units to relax the muscles than women, since they tend to have stronger face muscles. The lines above your eyebrow are called glabellar lines. The recommended dose for men is 40 units, while for women the recommended dose is up to 20 units.
The general guide for BOTOX injections from Allergan suggests 12 units around each eye for crow's feet, 20 units total above the eyebrows and 20 units for horizontal forehead lines. That is a total of 64 units to treat all three areas to help diminish forehead wrinkles and brighten your eyes. However, this is a guide and some patients may need much less for efficacy, anywhere from 10-30 units.