Character/Numeric TN LCD too Dim with a Head on View as Apposed to a Side View
LCDs are built with an "angle of view" specified in the datasheet. This is the optimum viewing angle, and it's determined by the orientation in which the LCD glass is put in the frame and, more importantly, by the way the glass is ground prior to laminating the LCD together.

If you need to be able to see the LCD from a different angle, flip or rotate it physically, and then counter-rotate the graphics in your firmware/software. If this isn't possible, order a different LCD or accept it as a learning experience.