The lighthouse was improved in 1908 with a new fog signal and a 38-foot (12 m) tower, which housed a fourth-order Fresnel lens. The light was automated in 1974. Today, it has a modern lens which flashes a white light once every six seconds and has two red sectors marking dangerous shoals off the island. The original fourth-order Fresnel lens, which was also used at the Alki Point lighthouse, is now in private ownership in Oregon.
The early years of the light were recorded in The Light on the Island, the childhood recollections of Helene Glidden, daughter of Edward Durgan who was lighthouse keeper from 1905-1913.