Is the light a Nimitta and when should one look at it?
When one practices meditation based on the breath, it is possible for the light to come and when that happens and it is stable one can use that light to enter samadhi absorption concentration. However, one should know when to look at the light and when not to look at the light. It is very important to know this difference because progress can stop. A long time ago, many teachers were telling their students to never look at the light. The teachers were not very developed and it was passed down from one teacher to another. Somewhere down the line, an experienced teacher gave the proper instruction of “not looking at the light” to someone who was not ready yet. This is proper, but if he had gone further and developed, he could have finally received the instructions to look at the light later on. So it was passed down from lay teacher to lay teacher and that was the general instruction long ago. That has changed, and now there is a push to look at the light as soon as it comes to the meditation yogi even though it is not stable yet. Ths can give little “highs”even if one is not ready, but that is not the way to practice and development will be hindered.
So when should one look a the light and not look at the light?
In meditation based on the breath, one should focus on the in and out breaths in the area between or on the exit of the nostrils and the top of the upper lip. Eventually, when concentration develops, one might see forms and shapes similar to what one knows as the breath. This is called a Nimitta in the Pali language. As long as you see an image, we can say there is some mental light because light is a cause for seeing. However, we often say that the object that is different from the nimitta is “just light” and that should never be looked at. Also, never look with your eye power. Your eyes are closed and one should “see” with the mind and not the eyes. The eyes should also be relaxed according to the Anapana samyutta. So you should always look at a nimitta if it is real and not look at the light. Eventually this image will get brighter and more “pure” looking. However, don’t judge it and don’t worry about what it looks like. When you are looking at the object, you will still know it as the breath, just like you know your fist when you look at it.
How to know if it is the nimitta or the light?
Make a fist and look at it right now. You can feel your fist and you can see your fist. They are the same objects. If you were to feel the fist and the image of your fist were in a different location, appearing here and there, bouncing up and down, violently shaking, etc., then you would not want to look at it. This is only just the light and it should be ignored. If your fist and the image are the same, then you should look at the nimitta. The same is true with the breath. The breath is to be known through touch sensation, but the touching sensation should not be the object because that will always change in qualities and characteristics. One should only know the breath as breath. It is a concept and without the details of how it feels (or looks). If you were to look at a bunch of vehicles as you passed them down a congested road, you should know only “vehicle” without paying attention to the shape, color or manufacture. Even if it is a truck or van and not a car, it makes no difference. The concept of “vehicle” never changes. It is “vehicle.” As the mind gets more concentrated on the concept of the breath, a mental image will appear. If it is bouncing here and there and not in the same place as the breath, or does not stick around for a long time, that is good, but not good enough. At this stage you are able to see the light, but not a nimitta. Keep trying focusing only on the breath. Eventually the physical breath and the mental image of the breath will become unified together. When that happens, you can drop the breath and continue to focus on the image. It will seem as though there is a phantom breath still present as you “see”, yet you are not feeling the breath. You are in a state of “knowing and seeing” the breath but not feeling the breath. This is good. You now have a pure Nimitta that is not mixed with the physical breath. Keep focusing in this way because these are the correct conditions for focusing on the nimitta. If you can sustain this for a long time, you probably already have samadhi absorption concentration. One can know for sure by looking at the heartbase and discerning the Jhana factors. When you get there, let me know. We can discuss further.
One last thing. One never actually looks at the light. Notice that I said “focus” on the light. I never said look at it. The light should appear in the mind. If you think you are looking at the light, you are probably using your eyes. Let it appear in the mind. So… as the previous teachers said, “Don’t look at the light” (especially if it is not a nimitta).