This could be a hint that Boruto’s eye is similar to the Tensiegan in that Toneri will help Boruto get rid of it so it can disappear. It might be a dojutsu that comes and goes and it has been doing so in the series so far.
Toneri from episode 8 clearly doesn’t mean harm, as he informs Boruto and warns him that:
- his eye is the star of hope
- his eyes will shoulder the fate of the world on his shoulders
- and that the light will guide him into the darkness
Sort of a prophecy, but I believe Toneri will help Boruto in the future, even though he is trapped on the moon, his chakra will resonate and help guide him as to his eyes not destroying the earth and the world as we know it.