Annapakshi Vilakku represents the kindling of the inner light of knowledge. The light of knowledge dispels darkness of ignorance.
The altar lamp serves to remind us of the highest aspiration of Hinduism – to awaken wisdom (praj?a). This aspiration is embodied in the Gayatri mantra which is a prayer for the enlightenment.
The same symbolism is found in the burning of a camphor flame and waving it around in front of the deity – it is prayerful gesture that the entire world will become enlightened. We touch the flame and then our eyes to indicate our own desire and aspiration for wisdom. Camphor melts away indicating the Self merging with the Supreme light of the Universe.