Hi, welcome to the forum, one can go through visual hallucinations which seen due to neuroophthalmologic dysfunction resulting from a wide variety of underlying etiologies. This condition can overlap with visual illusions which include distortions of size (micropsia or macropsia), shape (metamorphopsia), and color (dyschromatopsia).
The type of hallucinations you are experiencing is known as Complex or formed hallucinations as you see things with details like spider. In such cases it is very important to note any other conditions like eye problems, stress, confusion, memory loss, alcohol, drug, and medication history is also important.
It is good that it is working fine for you. Such methods are useful when the cause is more of psychological. This acts more like a suggestion therapy. It may be helpful for other people having similar symptoms. Take care and regards.