is
Enables or disables the eye distance scaling feature for this placemark. When enabled, the placemark's size is reduced at higher eye distances. If true, this placemark's size is scaled inversely proportional to the eye distance if the eye distance is greater than the value of the Placemark.eyeDistanceScalingThreshold property. When the eye distance is below the threshold, this placemark is scaled only according to the PlacemarkAttributes.imageScaleX / PlacemarkAttributes.imageScaleY.