The eye dome lighting strength value is a percentage (that is a value between 0 and 100). EDL is disabled when the value is set to 0. The default value is 50. A larger value will give you a stronger perception of the depth. Ensure that IsEyeDomeLightingEnabled is true for this value to have effect.
// get current EDL settings
bool isEnabled = lasDatasetLayer.IsEyeDomeLightingEnabled;
var radius = lasDatasetLayer.EyeDomeLightingRadius;
var strength = lasDatasetLayer.EyeDomeLightingStrength;
// set EDL values
lasDatasetLayer.SetEyeDomeLightingEnabled(true);
lasDatasetLayer.SetEyeDomeLightingStrength(65.0);
lasDatasetLayer.SetEyeDomeLightingRadius(2.0);