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 image formed on the retina is inverted (upside down) and real (the light rays travel through the image).
Nationally, professionally-installed radon mitigation system costs average $1,200, but range from $800 to $1,200 in Colorado, assuming there aren't any problems encountered during installation.*. Costs are highly dependent on what is required to vent the radon and how to route it through the house.
1 A radon test kit, including laboratory analysis, costs $15-$35. 2  Short-term test kits cost a little bit less than long-term test kits. 3  Radon test kits are available at most home improvement stores, including Lowes and the home section of Wal-Mart. Ventilating the home and crawlspace is a temporary and limited fix. 2  Passive and active suction systems cost $550-$2,500 depending on the size of the house. 3  These systems offer the best radon reduction available.