Pseudoexfoliation is one of the most puzzling, serious diseases of the eyes. Here are some reasons why it's so mysterious: 

• The cause of pseudoexfoliation is unknown
• In people with ocular pseudoexfoliation the material can be found in other body organs
• Some people have pseudoexfoliation in only one eye and others have it in both
• Why do only 33% of people with pseudoexfoliation develop glaucoma?
• Why is pseudoexfoliation much more common in women? 
• Some pseudoexfoliation glaucoma responds well to treatment and others don't
• Pseudoexfoliation cataract surgery is not difficult in all eyes
• Pseudoexfoliation is more common in some ethnic groups and countries
• Pseudoexfoliation is very rare under age 60
• Pseudoexfoliation  is very rare in African-Americans, even though they have a much higher  incidence of standard open angle glaucoma than white people
• Pseudoexfoliation is more common, geographically, in higher northern latitudes
• There  is an association between the incidence of pseudoexfoliation and  variants of the LOXL1 gene, yet not every person with the LOXL1 variant  has pseudoexfoliation