Visions of light and deities in meditation

The following website mentions Three Kinds of Pure Visions
http://www.berzinarchives.com/web/en/archives/advanced/dzogchen/basic_points/major_facets_dzogchen.html

those that arise from meditative experiences, those that arise in dreams and
those that arise directly to sensory consciousness – actually seeing and hearing while awake, not while dreaming or in meditation.

I have experienced all these visions in different times in my life.We all see dreams and can relate to that easily.

The third type of vision I saw was of Guru Gobind Singh Ji's Sikhs on horses with Gurur granth Sahib ji being carried in the front or middle of the four sikhs on horses. This vision I saw when I was 19 years old while bowing to the sikh sangat in a procession called Parbhat Feri, early in the morning, 4am. I was shocked, as I didn't think it was possible. I was awake and I knew in reality there were no Sikhs on horses and yet what I saw was so real and couldn't be denied.

The visions in meditation is what I have been experiencing this year. I was quite perplexed as to why did I see these deities in meditation. I can understand seeing my Sikh Gurus as I pray that they show me the path and give the right knowledge. I have seen Guru Nanak dev ji and can confirm that the old photo of Guru nanak dev ji is much more accurate. He was nothing like the usual calender showing Guru Nanak as a fair skinned and plum figure.

On last Firday morning, Guru Ram Das ji came and placed his hand over my head. I recognised him with his long beard. He was handsome and I was shocked as I never usually pray to him. I pray to Guru Arjan Dev ji but later I remembered that I had been thinking of him lately after hearing some of his Shabads that describe his mystical meditation experiences. He gave me a cotton cloth and placed it on my right knee. I looked at it and felt it was pretty ordinary cloth with big checked design. I was disappointed that it was not silky and velvetty and then thought it was so rude of me to think in this manner. So I excepted it and understood it to be for my protection. I remembered that in visual meditation explained in the book "Meditation and Dreanwork", the author suggested to take this imaginary cloth over like a shawl but when I looked at it, I wondered if it was big enough for that. I then remembered that I should thank him for giving whatever cloth he has given me, as that's what I deserve and may be that's the type of cloth that was available in the times he existed and possibly used himself but i was too late, he was gone. I thanked him anyway.

Meditation: Mystic Experience in Meditation - Visions Of Lights By Sri Swami Sivananda on the following website
http://www.experiencefestival.com/a/Meditation/id/23789
has written a very good article explaining the stages of meditation and how we shouldn't get caught up in what we see as the colours and deities are just encouragement for us to continue, not the end product.

I have seen the purple light in the third eye several times but then I started having other experiences without seeing the light. I was worried about that. The article had made things clearer to me.