Botox is the trade name for botulinum toxin. In its pure
form, botulinum toxin is a type of food poisoning that causes muscle weakness.
It acts as a nerve impulse blocker, preventing muscles from contracting. In an
extremely dilute form, botulinum toxin has many medical applications.
Botulinum toxin can be injected directly into muscles of
the face or eye when facial muscles are overactive. Botox causes the overactive
muscles to relax. It usually takes a few days for the therapeutic effect to be
noticeable. The injections may need to be repeated every 4 to 6 months.
Botulinum toxin is used in ocular conditions such as
blepharospasm, an excessive contraction of the eyelid muscles that forces the
eyelids closed, and hemifacial spasm, an excessive contraction of the facial
muscles on just one side of the face. For certain types of double vision,
botulinum toxin can be injected directly into the eye muscle opposite the
paralyzed eye muscle. Some wrinkles also become less prominent if injected with
Side effects of the injection are temporary. They can
include a droopy upper eyelid, double vision, and inability to close the