# Numerical Simulation on Corneal Surface Behavior Applying Luminous Beam Levels
## 4 Discussion  
When comparing the results obtained numerically, there is a variance in the values obtained experimentally in the research contemplated. The outcomes in the validation are considered to have an absolute error of 3.2%. This error may be due to the patient's age, the dimensions of the parts of the visual organ, and the mechanical properties. The age of the subject for this research was a 72-year patient. Therefore, the variance in the graph is considered; due to age-related health conditions, there were significant deformations generated. The graph retains its characteristic curved shape, validating that the model and the analysis proposed employing the characteristic equation of the Ogden model satisfy the characteristic curve for viscoelastic materials. The values obtained in the five cases are presented in Table 5 to compare them. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Case**} & **Power** & \multirow{2}{*}{**Source**} & **Distance** & \multirow{2}{*}{**Photon Load (Pa)**} & \multirow{2}{*}{**Photons**} & **Total Load** \\  & **[W]** & & & & **Applied (Pa)** \\ \hline
1 & 0.1 & Sun & 200 & \(6.966\times 10^{-15}\) & \(15.106\times 10^{16}\) & 1052.2616 \\
2 & 0.0857 & Sun & 200 & \(5.99\times 10^{-15}\) & \(15.106\times 10^{16}\) & 905.8763 \\
3 & 0.5 & Smartphone’s screen & 200 & \(4.5439\times 10^{-15}\) & \(157.85\times 10^{16}\) & 7172.637 \\
4 & 0.01 & Commercial laser & 200 & \(2.09022\times 10^{-15}\) & \(5.0474\times 10^{16}\) & 105.22616 \\
5 & 1 & Commercial laser & 200 & \(1.3934\times 10^{-15}\) & \(755.12\times 10^{16}\) & 10,522.62 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Power values per case. Figure 9: Node selection boundary conditions. Initially, we have the decrease in charge that an individual photon can generate. This is due to the different wavelength levels; the more influential the wavelength, the less charge it causes. This can be seen in cases 1 and 2; although the numbers of photons are the same, the total incident charge and the displacements decrease. Specifically, case 3 is considered, for a screen of a smartphone at the minimum brightness of 200 mm; the generated charge is relatively high, and if the maximum brightness is considered, which is 1.5 W, it is estimated that the deformations increase. Because of this, it is possible to define the loads generated by luminous devices due to the amount of energy used to display clear and sharp images; therefore, it causes significant amounts of loads that are not lethal but can generate a constant load. Inconsequential fatigue failures due to repeated loads of non-infectious injuries, such as exposure to brightness over long periods, can cause damage to the eyeball, specifically on the corneal surface, causing eye diseases and blindness [33]. On the other hand, cases 4 and 5, which are commercial infrared lasers, show the importance of the electrical power by which the light source is supplied, because greater watt consumption by the source produces more photons and is directly proportional to the amount of load. Finally, the charge a photon generates depends on the electromagnetic spectrum to which it belongs. The direction a photon can generate is inversely proportional to its wavelength features. The analysis specifies that the deformations in the elastic region were due to the incident charges. Each case has a different result depending on the wave size and the power of the source. These case studies could even be extrapolated to cases where the cornea is subjected to extreme loads, such as refractive surgery, using a laser with specific characteristics, or proposing a photorefractive keratectomy (PRK). Alternatively, a current technique called Laser-Assisted in Situ Keratomileusis (LASIK) uses an ultraviolet laser. According to their datasheets, Table 6 shows the types of wavelengths for both cases.