## 4 Discussion  
It has been widely described that the effects of light on human health and well-being depend on factors such as its action spectra, intensity or timing, searching for an \"integrative lighting\" situation in which visual and nonvisual human behaviors are comprehended [30; 31]. In this sense, the standards that regulate building lighting have been recently modified to promote the incorporation of nonvisual considerations in lighting \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Standard Illuminant D65**} & \multicolumn{3}{c}{**Standard Illuminant A**} \\ \hline  & \(\mathbf{MAF_{trans}}\) & **EDI lux** & **EML lux** & \(\mathbf{MAF_{trans}}\) & **EDI lux** & **EML lux** \\ \hline Without age & \multirow{2}{*}{0.906} & \multirow{2}{*}{200} & \multirow{2}{*}{221} & \multirow{2}{*}{0.449} & \multirow{2}{*}{99} & \multirow{2}{*}{109} \\ considerations & & & & & & \\ \hline
10 Years & 0.923 & 204 & 225 & 0.448 & 99 & 109 \\ \hline
20 Years & 0.917 & 202 & 224 & 0.448 & 99 & 109 \\ \hline
30 Years & 0.908 & 200 & 221 & 0.449 & 99 & 109 \\ \hline
32 Years & 0.906 & 200 & 221 & 0.449 & 99 & 109 \\ \hline
40 Years & 0.897 & 198 & 219 & 0.451 & 100 & 110 \\ \hline
50 Years & 0.883 & 195 & 215 & 0.452 & 100 & 110 \\ \hline
60 Years & 0.866 & 191 & 211 & 0.454 & 100 & 111 \\ \hline
70 Years & 0.847 & 187 & 207 & 0.455 & 100 & 111 \\ \hline
80 Years & 0.827 & 183 & 202 & 0.456 & 101 & 111 \\ \hline
90 Years & 0.806 & 178 & 196 & 0.457 & 101 & 111 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Changes in circadian lighting (EDI and EML) for D65 and A illuminants reaching the retinal plane depending on the age of the subjects, considering 200 photopic lux at the corneal plane. Calculations without age considerations match with a standard observed age of 32, as described in the current normative. Abbreviations: \(\mathrm{MAF_{trans}}\), Melanopic Action Factor considering transmittance of the lens; EDI, Equivalent Daylight Illuminance; EML, Equivalent Melanopic Lux. Figure 4: Chromatic diagram representing the location of the D65 and A standard illuminants by optical density and age, from 10- to 90-year-old observers. **Left**: D65 illuminant. **Right**: A illuminant. projects, in particular, the age of the people in a specific room [32]. There are other lighting standards or recommendations integrating those effects, though these standards are in progress and not yet fully agreed on, even criticized by other stakeholders [29; 33; 34]. Before light excites the photoreceptors, it is modified (relative to the corneal plane) by passing through the pupil and the ocular media. These parameters depend on the eye of the population evaluated and should be taken into consideration in this type of study [35]. An ideal situation would be to perform subjective analyses of lighting scenarios in groups of observers with different age ranges [36], but lighting designers need to have a tool to predict circadian contributions in their lighting projects. Obviously, the general population does not fall near the standard observer aged 32 years, and particular characteristics are intrinsic to each eye, but a rule is needed to preview different real situations. Perhaps calculating age-dependent effects on prereceptoral filtering, along with reporting the retinal intensity of light calculated from the spectral radiance by multiplying with the pupil area, should be recommended since natural pupillary miosis is highly age dependent. In this sense, it has been described that responses to blue light, and in consequence melanopsin-dependent pupillary miosis, are preserved in healthy aging and cataracts, suggesting that both pathways (visual and nonvisual) adapt to the yellowing of the lens to maintain the constancy of the light responses [37], although when retinal or optic nerve diseases are present, it should be particularly evaluated [38].