Current and future life sciences demand more data for experiments, modeling and computing. After introducing Photosynthetically Active Radiation (PAR), the quality of light was sacrificed for the quantity. PAR has an intrinsic drawback that stems from reporting light sources by a number of the irradiated quanta. In pieces of research on photosynthesis, PAR generally and appropriately is used, whereas PAR has been inappropriately used in pieces of research not dealing with photosynthesis directly as a parameter. Different light sources have diverse spectral photon fluxes (SPF), both in and out of PAR region, which can affect the results of a research quite apart from measured light intensity in PAR. Here, many published papers about light quality effects on plant growth and development are reviewed. In addition, PAR disadvantages and SPF-based extended PAR (EPAR) advantages are discussed to show that a quantitative unit cannot be sufficiently informative where photosynthesis is not the sole parameter. Instead, EPAR is proposed to be considered for research on plants and reporting the results to provide more and detailed information.