The ABCD matrix is one of the essential mathematical instruments in optics.
It is the two-by-two representation of the group Sp(2), which is applicable to
many branches of physics, including squeezed states of light, special
relativity and coupled oscillators. It is pointed out that the shear
representation is oriented to binary logic which may be friendly to computer
applications. While this is a future possibility, it is known that para-axial
lens optics is based on the shear representation of the Sp(2) group. It is
pointed out that the most general form of the ABCD matrix can be written in
terms of six shear matrices, which correspond to lens and translation matrices.
The parameter for each shear matrix is computed in terms of the three
independent parameters of the ABCD matrix.