Light from an object passes through the cornea which is a transparent dome like structure covering the iris. The light rays are refracted by the cornea onto the lens. The light rays are refracted a second time whilst passing through the lens and focussed onto the retina â the light sensitive part of the eye.
The average Radon mitigation cost in Portland, Oregon, or Vancouver, Washington is between $800 to $2,500 with an average of $1,200.
1 The EPA's Installation and Operating Cost Table lists how much a radon mitigation system should cost based on the type of foundation. 2  Operating a radon mitigation system costs from nothing up to $700 per year. 3  Many radon mitigation systems have fans that require continuous electric power that can add to power bills. It's wise to retest a home's radon level every year or two after a mitigation system is installed. 2  Most radon mitigation systems include a fan, which will need to be replaced about every 5 years. 3  Expect to pay $250-$300 to have this necessary maintenance done.