Concentrating on light is one of the most effective, most powerful exercises there is. But never forget that the effect something has on you depends on your attitude towards it.
If you consider it useful and magical, you amplify its effect.
Through your thoughts and convictions, you have a decisive influence, which is indeed far more important than the objects or conditions themselves.
Light can penetrate you without your being aware of it of course, but if you are attentive and full of good-will to participate in its work, with the conviction that something is growing and developing within you, you will gradually sense the vibration of new forces.