Photogray Lenses Incorporate Small Amounts of Silver Chloride in the Glass

Essay

Photogray lenses incorporate small amounts of silver chloride in the glass of the lens.The following reaction occurs in the light,causing the lenses to darken:
AgCl $\to$ Ag + Cl
The enthalpy change for this reaction is 3.10 $\times$ 10² kJ/mol.Assuming all this energy is supplied by light,what is the maximum wavelength of light that can cause this reaction?