Landed in HPN (White Plains) back in 1979-1981. Air Florida taxiing out....just the vertical stabilizer was visible. Ground fog from the lake just NW of the airport. Common early morning problem in the spring/fall. We could see the approach lights all the way down...until 10-15'? FO is looking down outside his side window saying "lower, lower, lower....." I could see the runway lights but had zero depth perception.