In this opinion, there is no prohibition on natural “deception of the eyes,” provided that the natural means of the tricks are declared in advance. Based on a statement of Chinuch (250), the Kloisenberger Rebbe (Divrei Yatziv, Yoreh De’oh 57) also writes, in a speculative rather than Halachic manner, that one may be lenient, as long as the magician makes it clear that no supernatural forces are involved.
In conclusion, it is worth noting that even those who are stringent regarding “slight of the hands,” may concede that today no prohibition would apply. As the Rambam and the Chinuch (250, at greater length) conclude, the evil of “deception of the eyes” is that people will come to believe the impossible to be possible, and even reach conclusions that contravene the basic Jewish faith.
Nowadays, this scenario is quite implausible—which is perhaps the background to the difference in approach of later authorities, such as the Iggros Moshe and the Klausenberger Rav, in comparison with the stringency of earlier authorities. The first question that a child raises after a magic trick is performed, is “How did you do it?!” He clearly doesn’t believe that the word “abracadabra” in able to achieve miracles, and supernatural forces are surely the last thing on his mind.
If the audience is fully aware that the magic tricks are nothing but natural deceptions, then the argument for leniency becomes most convincing. Naturally, there is no issue of “theft of the heart,” for nobody is tricked into believing in supernatural forces; as for sorcery, we find no source to prohibit “deception of the eyes” under such circumstances.
Rav Moshe Sternbuch (Teshuvos Ve’hanhagos 1:655) also mentions, in the name of the Chazon Ish, that no prohibition applies when the audience is aware that it is only a trick.
Yet, it should be noted that there are many types of magic shows and acts, the more sophisticated of which may well enter the fray of the halachic dispute. Before ordering the next magician—and surely before entering the profession—it might be wise to consult a halachic authority.