Holmes-Wright Lantern
The Holmes-Wright Lanterns were a series of Lanterns for color vision testing used by workers – both civilian and military – in the British marine and aviation industries. The Lanterns were created in 1974 to replace the Board of Trade Lanterns. They were replaced in the UK by the CAM Lantern in 2002.
There are two variants of the Lanterns, with the B-Lantern used in the UK Merchant Navy (Board of Trade) and the A-Lantern used in the UK Navy, RAF and civilian aviation.
Compared to the Farnsworth Lantern, both version are much stricter (harder to pass). Of 100 subjects with CVD, one third passed the Farnsworth, 14% passed the A-Lantern and only 2% passed the much harder B-Lantern (Vingrys 1983). Actually, even 8% of color normals failed the B-Lantern, making it a very strict test.