Kandariya Mahadev temple at Khajuraho was constructed in a way that only appropriate light was allowed in the mandapas through half walls
Light is one of the most important elements of the temple design. It has always been used very thoughtfully in the temple designs. From the glare of sunshine, as one enters the temple, the experience is that of moving inwards through gradually darkening spaces and finally to the innermost sanctum, which is in almost total darkness.
To understand the methods used to achieve the desired light quality in the ancient Hindu temples, a detailed research project will have to be taken. Some studies have been undertaken in this aspect and it was observed that whatever may the size and the type of the temple be, the quality of light in the Garbha Griha, Antarala, Mandapa or in the Ardha Manda was always as expected. Depending upon the climatic conditions of the region where the temple is located, the provision of entry of the light was very thoughtfully made. The sizes and designs of the windows, zarokas or entrance doors etc. are changed to achieve the quality of light at that part of the temple.
Garbha Griha, which is the innermost sanctum, is the place where one is supposed to be intimately connected to supreme Brahma. Presence of the smallest ray of light might have been considered as a source of distraction. Warmth and darkness of mothers womb is attained here by the designers.
The Hindu religious belief is that when man is in the presence of the divine, there should be nothing to distract his eye and that God shall reveal himself to his devotee gradually. Example of Kandariya Mahadev temple at Khajuraho demonstrates the principle in totality. The Garbha Griha is dark and appropriate light was allowed in the mandapas through half walls.
The cravings on the walls and interiors of mandapas and other spaces corresponded with the amount of light in that space. Thus Garbha Grihas were mostly plain and devoid of any carving.