The third eye comes from a gland in the brain known as the pineal gland. The function of this gland was completely unknown until late 50s/early 60s when they discovered that it produced a chemical called melatonin. It happens that the gland is shaped like an eye and lies between the hemispheres of the brain in such a way to be between back to your actual eyes. Its position as an eye is reminiscent of certain eastern concepts, the most obvious being the Indian tradition of the dot on the forehead indicating the third eye.
Up till the point where its function was discovered, occultists claimed that the gland was an eye into the spirit world, and scientists believed the gland to be a "vestigal remnant" which is an organ which has lost its function in modern society.
Although several other old religions have used the concept of the third eye, its very likely they had examined a dead body and discovered the pineal gland and mistook it for an eye inside the head.
In the 50s/60s, the purpose of the gland was discovered. It is what you might call the biological clock. It produces chemicals to regulate sleep cycles. When this was discovered, the occultists switched the concept of third eye to a more mystical spiritual concept. However, no one has actually been able to demonstrate that any third eye actually exists.
Nobody has been able to show any knowledge of the future. The most famous person to try is Nostradamus. However, you will notice that despite hundreds of poems, his predictions are all very vague and subject to a wide degree of interpretation. Nobody knows if his predictions have come true, but every time a major event happens, someone finds a vague quatrain that might match up with it.
So, I am sorry to say, but it seems that no one can see the future.