LENS REPLACEMENT SCHEDULES

Until recent years, contact lenses were 
prescribed to patients and used by the 
patient until they were broken, torn, 
lost or deposited to the point they had 
to be replaced.  With PMMA lenses this 
could be as long as 10 to 20 years.

With the introduction of hydrogel 
lenses, they were easier to tear and 
deposits that could not be removed 
developed more rapidly.  One to 2 
years was usually the useful life.

Rigid gas permeable (RGP) lenses are 
more brittle than PMMA lenses and 
usually do not last as long, commonly 
1 to 3 years.

Lenses prescribed in this fashion are 
commonly said to be worn on a 
conventional replacement schedule.