Vault Lights or Pavement Lights are those old glass blocks set into pavements to let light into vaults and basements below. The glass used would form a not-very-bright spot on the floor below, not providing much useful general lighting.

The idea originated in the 1840s as deck lights. They were used on ships to let light below-decks, especially when an open flame would be hazardous.
The idea caught on; by the late 19th century they were common in larger towns. Their use declined as electric light became cheaper and better, and by the 1930s were on their way out. After 100 years of pavement traffic, they usually look like this, with most of the glass broken out then filled in, with a few brave soldiers holding the fort.

Pavement lights have come a long way in 100 years.  We at Limitless Ltd design bespoke alternatives to these units or one of a couple standard designs as below.  These are ventilated, let a lot of daylight travel far into a basement room, even on a cloudy or overcast day the difference is astonishing. 

BEFORE – Internal view

AFTER – Internal view

BEFORE – Internal view

AFTER – Internal view

BEFORE – Internal view

AFTER – Internal view