Wikipedia has more on Catoptrophobia
Catoptrophobia (from Greek catropto or katoptron, mirrors), also known as spectrophobia (from Latin spectro (ghosts), and eisotrophobia (from Greek eis (into) and optikos (vision)) is the fear of mirrors. The phobia might be conceived due to the person not agreeing with their beauty or body image in the mirror, especially by obese people, or even the presence of the supernatural.
Many cases of catoptrophobia are traced back to mankind’s fear of still waters. The reflections in still waters are often thought that “it was their soul staring back at them”. This gave rise to the concept that the ‘soul could be separated from the body even before death’. Many folktales were also developed around this concept. For example, there is a story about the disturbance in a character’s reflection in a lake that eventually leads to impending doom or disaster. This led to association between shattered/broken mirrors and bad luck/death. Till date, a mirror shattering implies “seven years of bad luck”. Many African tribes also associate reflections in dark still waters with death. They avoid looking in such waters, as they fear that crocodiles/evil spirits can kill them by simply snapping away at their reflection and taking away their souls. In several cultures, children less than a year old are not shown a mirror due to the belief that they might die when shown their reflection. Similarly, in certain cultures, mirrors in households where death has occurred are kept veiled so that mourning family members do not see their reflection (or they too would die soon). Brides are prohibited from looking in a mirror when dressed in their wedding finery. (However, as a couple, the newlyweds may look in the mirror together since this is auspicious). Thus, mirrors have many superstitions associated with them. These superstitious beliefs can easily create fear of mirrors in young or high strung/anxious individuals.
Sufferers would avoid looking themselves in the mirror. If so, they would have effects including trembling/shaking, thoughts of death or dying, screaming, crying, trying to flee, rapid heartbeat, shallow breathing, dilated pupils, sweating excessively, full blown anxiety or panic attacks.
Taking baby steps is the best way to overcome
Exposure therapy can help an individual slowly progress to overcoming his fear once and for all by looking at images of mirrors, thinking about mirrors and then finally progresses to holding and looking inside one. Homeopathic remedies, including herbs, lavandula, chamomile, melissa officinalis can also help relieve anxiety associated with the phobia. Talk therapy, online and offline support groups etc. can help the phobic give vent to his fears. Family and friends should support the phobic individual rather than teasing or making fun of him. NLP therapy, hypnotherapy and psychotherapy are some other methods that are effective in treating the fear of mirrors.