Purpose

• A pinhole test determines the cause of blurred vision.glasses reflecting in the glass tabletop image by Daria Miroshnikova from Fotolia.com
  
  The pinhole test helps to differentiate between two types of blurred vision. A patient's blurred vision might be caused by a focusing problem, which can be corrected by glasses or contacts, or it may be caused by a disease. A properly conducted pinhole test will pinpoint the source of the problem.
  
  

Method

• The pinhole test can be conducted at home.hole image by Vaida from Fotolia.com
  
  A pinhole test is very simple but very useful; it can even be conducted at home with a piece of cardboard material perforated with a pin tip to create a pinhole about 2mm in diameter. The person suffering from blurred vision should select and focus on a distant object. Then, with one eye at a time, she should focus on that same distant object through the pinhole in the card.
  
  

Results

• Blurred vision through a pinhole is a possible indicator of disease.eyes image by Mat Hayward from Fotolia.com
  
  If the distant object appears sharper through the pinhole, then the subject likely has a simple focusing problem that can be addressed with corrective lenses. However, if the distant object is still blurry through the pinhole, the subject should contact an eye doctor immediately, as this could be an indicator of disease.