The two physical eyes have functions beyond commonplace seeing capabilities. The first eye- the right- is basically used to see the forms of objects; it helps in sensitivity of detail. The second eye- the left- associates with one's emotional self, more to colour and texture, compared to form; it furnishes humans with a sense of the relationship between objects.
The third eye gives one perception of the form and workings of the physical world; it expands on what the first eye sees and fetches depth or a third dimension. After opening, it brings height into position, lessening fear of heights or of flying. The fourth eye is for understanding relationships and developing a faith in God; it expands on what the second eye views. The fifth eye helps in interpreting universal truths and ideals; with it, one receives "concepts" and it is brilliant for past life viewing. The sixth eye is necessary for true inner sight and for interpreting the core and purposes of one's lives. The seventh eye helps in interpreting the entirety and purpose of the universe; through it, one receives heavenly understanding and sees glowing light and angelic presences.
Few people have all seven eyes matured; fewer, in fact, have even the first two eyes totally developed. This is basically due to ignorance of the possibilities in the diverse forms of sight, one's idleness in grasping or "seeing" what the eyes essentially perceives and inadequate regard for the spiritual heritage of expanded cognisance. All these attitudes casts mask over the eyes; but when one removes them, new worlds open up.
The Danger of Premature Opening
There are dangers in premature opening, the primary one being lack of comprehension and fear of what is not understood. People's eyes may "blow" open prematurely through drugs, physical wound (a head blow, for instance), or through uneven development of the evolutionary process. Whatever the reason, when an eye opens without one's full perception of its purpose, puzzlement and misinterpretation ensues; what should be a blessing, may feel like a curse.
The Subconscious Eye
It is also called "First Consciousness" Eye. The subconscious eye is located at the top of the nose, in the indention beneath the bones that rise up to form the brow. It is an area of mutual physical and emotional consciousness and as such concerns with one's basic or primal living, gut level feelings, basic survival and awareness. With this chakra open, it puts a person in touch with the subconscious (which is not supposed to be subconscious at all). Any emotional or physical difficulties which a person prefers not to deal with in a conscious level create blocks, subduing growth and consciousness.
When the chakra is too open, a person suffers obsessions with physical and emotional matters; if it is too closed, the person is out of touch with life force. A signal that this eye is beginning to open- that subconscious information is coming to cognisance- is an impulse to massage.