In 1868 the lantern stage (the top-most part of the tower) was replaced with the then-innovative diagonally-framed glass structure seen today.

Following this, the reflectors were replaced in each lighthouse by a large (first-order) catadioptric lens designed by Chance Brothers of Smethwick.

In 1871 Happisburgh's lighthouses were used for a series of trials comparing a Douglass 4-wick oil light (displayed from the low lighthouse) with a Wigham 108-jet gas light (displayed from the high lighthouse) both using the same optics;[3] the experiments (which tested rival claims made by the principal advocates of these forms of illumination, James Nicholas Douglass and John Richardson Wigham respectively) were not conclusive and further trials later took place at South Foreland.

The low light was decommissioned and demolished in 1884 before it could be lost due to coastal erosion; its lantern and lens were reused at Southwold lighthouse.

[8] In 1987 Happisburgh was one of five lighthouses declared redundant by Trinity House and deactivation was planned for June 1988.