"He was my whole world," Eyster's daughter, Barbara Edgar, told The Citizen Friday morning.
Eyster began collecting Florida Keys historical artifacts in 1947. He was a board member of the San Carlos Institute in Key West and founded the Matecumbe Historical Trust in Islamorada.
Eyster and wife Jeanne were recently honored with a plaque on the Pacific Reef Light cupola in Founders Park. Eyster donated the lighthouse's lantern to the village from his collection.
Eyster, who suffered from Parkinson's disease, had been in declining health in recent years.
Edgar said he was admitted to Mariners Hospital Thursday morning. The cause of death is not yet known.