Hi and welcome!
I found your camera's manual here:
http://www.olympus.co.jp/en/support/imsg/digicamera/download/manual/zoom/man_fe230_e.pdfI did not find any indication on where to change the LCD brightness. Usually these things are adjusted in Setup menues.
One thing is sure, no LCD should be TOO bright to see pictures! Usually what happens is quite the contrary, especially in bright sunlight. It might be worthwhile to contact Olympus with this.