Parama Vyoma is the third ridge in luminous space or heaven and is mentioned in Rig Veda (9.86.27). It is the term used to refer to the highest space or highest heaven in ancient Hinduism.
The expresstion Parama Vyoma refers to the highest firmament of heaven in space. The term vyoman: vi-yoman vi-yu – heaven or div is commonly termed vyoman, the ‘luminous space.’
The three heavens are often called the three luminous spaces: the highest (parama vyoma or uttama), the middle, and the lowest (Rig Veda 5.60.6).
The highest heaven is also termed uttara or paraya (Rig Veda 4.26.6 and 6.40.5) or tritiya (Rig Veda 9.74.6 and 10.45.3) where the waters and soma reside. In the Parama Vyoma, the fathers and soma dwell.
Vishn, ancestors and Yama, eternal light and time reside here. The place is free from impurity (Ahirbudhnya Samhita 6.22).