What is the average horizontal visible iris diameter (HVID)?

The average horizontal visible iris diameter (HVID) is a crucial measurement in optometry and contact lens fitting. The generally accepted average for HVID is approximately 11.5 mm. This measurement is important for determining the appropriate size for contact lenses and understanding ocular anatomy.

When considering the average HVID, 11.5 mm represents a typical diameter for adults. This standard aids eye care professionals in creating a comfortable and effective lens fitting, ensuring that lenses are neither too large nor too small for the iris.

While other values may be mentioned in different contexts, 11.5 mm is widely recognized and supported by clinical guidelines. This makes it the most suitable answer when evaluating the average size of the visible iris diameter.