About a month or two ago, an iRL friend of mine found Daniel Ingram's Mastering the Core Teachings of the Buddha and started doing meditation practice. Since he had done things involving concentration practice before, he made rapid progress. Inspired by his practices and partially because I'd so quickly lost my position as being the superior meditation guru of us two, I too started making attempts at meditation again.
On a Monday maybe three weeks ago, I realized that something had clicked. You know that thing when you try to learn a skill, spend a long time being bad at it, and then suddenly one morning you wake up and realize that you're suddenly good at it? That happened to me and my concentration ability: concentrating on just one thing felt easier in an almost qualitative way, and was far less frustrating.
I reached the first samatha jhana the following day, the first time since my only previous jhana experience last summer. I put myself in the first jhana several times afterwards (including once while walking next to a noisy road), and also tried doing some noting practice. Suddenly I was using almost all available opportunities to do concentration practice, like when I was preparing a sandwich snack. I also thought about the Three Characteristics a lot.
On Friday that week, I woke up in the morning and turned on the lights. The first thing that I happened to look at was the back of my hand (which I'd just used to turn the lights on), and I was startled to realize that I was seeing in it far more details than I'd done before. When I looked around me, I could see details of things jumping out at me in a way they hadn't done before. While looking at a fantasy map on my wall, I noticed the names of the different regions for pretty much the first time - previously I'd only looked at the "big picture view" of the map. Things also looked sharper somehow, as if I'd just gotten stronger glasses.
I expect that if I'd done meditation practice at this time, the effect might have become permanent. As it was, I didn't have the chance as I had promised to go see a friend. By the time I got back home, six hours later, my perception had gradually faded back to normal.
For some reason, this caused a longer interruption to my practice. Getting to the first jhana felt more difficult, and I lost my inclination to keep doing concentration practices all the time. This might have had something to do with the fact that the noting practices had made it more difficult to really try to solidify any emotion, since I'd just been trying to think of them as impermanent. For a while, I was basically unable to meditate while at home, though for some reason I noticed that getting to a very light first jhana was still possible if I was walking outside. Sitting still at home, though, not much luck.
Then a while later, I decided to try out tranquility meditation. The first time, recalling a time when I'd felt happy and using the way I had felt as my concentration focus, felt quite nice, and I think I got to the first jhana. Unlike my previous jhanas, it was almost entirely lacking the irritation of needing to constantly maintain the feeling.
My next attempts at tranquility meditation fared worse. Using feelings of happiness as an object became harder, because for whatever reason, I suddenly had difficulties recalling my feelings on occasions when I'd felt happy, or indeed recalling any occasions when I'd been happy in the first place. And there was again the thing about having difficulty solidifying anything, feeling included.
So after some days, I decided to use the breath as an object instead. Now, there had been *one* lasting effect from that one Friday: I had briefly done some meditation on the way to my friend, and thought that I could see faint lights even with my eyes closed. And those lights had began to show up on later meditation sessions, as well. They don't seem to be *entirely* hallucinatory, since they are clearly stronger when I'm meditating somewhere well-lit, but I have also seen a much weaker form of them when when meditating in total darkness.
So this time around, I was doing tranquility meditation with the breath as an object, and I began to really notice the lights. Mostly I seem to sort of see them from the corner of my (closed) eyes, and if I try to focus my attention to them I'm not sure if I'm actually seeing any light at all. Now however, there were times that they got strong enough to persist when focused on, and I could follow them as they moved about in my visual field. They also seemed to work as feedback - when I e.g. focused on a feeling of tension and tried to let it go, the lights got considerably stronger. In general, they seemed to intensify whenever I was doing "the right thing".
I seemed to get quite strongly into... something, not entirely sure what. Some sort of jhana, I suppose. There was a feeling of movement, and my body seemed to grow heavy and slightly numb, with all sensation in the region around my head, where the lights were and where I'd also been focusing on some tension. Something seemed to be happening, but I wasn't sure of what.
When I emerged from meditation, I had an odd feeling, pretty close to how MCTB describes the first vipassana jhana, Knowledge of Mind and Body. I also seemed able to visualize things more vividly. I meditated two more times that day, though I didn't get an equally strong experience from those occasions, and I think my mental state actually faded back towards normality during them. On the third time I also got rather drowsy (I guess I hadn't slept enough that night), and ended up feeling drowsy for the rest of the day, unable to get much done. By evening I was feeling rather normal again.
That was yesterday. This morning I started with some more meditation, which went roughly the same, though again my experience wasn't nearly as strong and I didn't seem to get as deeply into it. Part of this was probably that I couldn't decide how to act regarding the lights: should I treat them as feedback but essentially ignore them, e.g. keep doing the things that made them stronger but not particularly focus on them? Or should I try to gradually shift from using my breath as a focus to using them as a focus? Or should I do neither, just treating them as yet another observation to be noticed and then let go? I think I instinctively did whatever the "right" thing was before, but I can't remember what that was.
I also made a tentative observation that I might be able to reverse the causality with the lights: e.g. usually when I'd let go of a thought, the lights would get stronger. On a few times, I tried instead making the lights stronger, thereby letting go of the thought. I'm not really sure if it worked, though, since on most occasions the thought still seemed to be there when my attention "got back" from the lights.
When I stopped meditating today, I again had a slight Mind and Body-ish feeling, but it was much weaker and also faded much quicker than on the first time.