Recently, Formal Concept Analysis has proven to be an efficient method for the analysis and representation of information. However, the possibility to visualize concept hierarchies is affected by the difficulty of drawing attractive lattice diagrams automatically. Reducing the number of edge crossings seems to increase the readability of those drawings. This work concerns with a mandatory prerequisite of this constraint, namely the characterization and visual representation of planar lattices. The manifold existing approaches and algorithms are thereby considered under a different point of view. It is well known that exactly the planar lattices possess an additional order "from left to right". The aim of this contribution is to define left-relations and left-orders more precisely and to describe several aspects of planar lattices with their help.