Mujitsu and Tairaku's Shakuhachi BBQ

Both Meian and Myôan are correct. Basically personal preference makes one or the other the preferred version.  In the Kansai (Kyoto/Osaka) area in the 1970s, one heard/saw Meian the most. Now, one hears/sees Myôan as often. The first character of the word can be read either way.

According to my Japanese-English Kanji dictionary, there are over 15 different pronunciations for the character 明 depending on the context: mei, myô, min, a, aka, aki, akira, ake, asu, kira, ke, saya, sayaka, toshi, haru, mi, me.

However one pronounces it, the character still means light or bright, or something to do with light. The character is itself a combination of two characters 日 'sun' and 月 'moon'.