Sally Kempton

 "The Kena Upanishad says that the Self "shines through the mind and senses," which is a poetic way of saying that it is the power of the Self which allows the mind and senses to function. So the eternally conscious Self is what makes us conscious. Essentially, it is light.

At times when our inner vision becomes pure enough to let us see through the layers of psychic debris that thickens our consciousness and make it opaque, we realize that everything is actually made of light. We understand that we are light, that the world is light, and that light is the essence of everything. This is why so many people's experience of touching the Self are experiences of light - visions, inner luminosity, or profound and crystalline clarity."