Beacuse most doctors use their Refractors all day, everyday, it is very easy for a decrease in performance to go un-noticed, because it happens gradually. Many people do not realize just how far the performance has slipped until they get it back after a Preventive Maintenance and wonder whether or not they received the right instrument!
Aside from the obvious, such as patients saying they cannot see the chart, here are a few things to think about or look for when deciding if it is time to get your instrument serviced.
How long has it been since your refractor was last serviced?
While you would never consider letting your car go 50 thousand miles between oil changes, how many refractions have you done since your intrument was last serviced?
We recommend an annual Preventive Maintenance and strongly urge you not to wait more than 2 years between services.
Just to give a quick example, one small part of a PM is removing the dust & dirt which accumulate in the lens dial detents. These are small spring loaded rollers which stop the lens dials in the correct spot. When they are not cleaned, dirt clogs up the rollers and they stop rolling. The lens dial will still stop, but each revolution wears a little of the plastic off the roller until it is no longer round. Eventually the dial will no longer turn. There are 6 of these detents in every refractor and they average $50.00 each (depending on the manufacturer), nearly the cost of a complete PM.