The mechanism of argon laser retinal photocoagulation (ALRP) treatment is to apply thermal-induced retinal pigment epithelium damage. Light passes through the anterior optical segments of the eye to reach the retina. Lens densitometry is a noninvasive and quantitative measurement providing information about corneal and lens clarity. This study aimed to investigate whether laser light affects lens clarity and corneal endothelial cells. This was a prospective, cross-sectional study. Lens densitometric (LD) analysis and specular microscopy were performed before, after, and 1 month after ALRP treatment, by an expert ophthalmologist, blinded to the medical status of the patients. LD analysis was performed using a Pentacam HR (Oculus, Wetzlar, Germany) and a Specular Microscope CEM-530 (Nidek, Japan) was used for endothelial cell analysis. The evaluation was made on 81 eyes of 41 patients, with a mean age of 54.46 ± 6.7 years. LD, after ALRP, was significantly more than before ALRP (p < 0.001). There was no statistically significant difference in LD, before ALRP, and 1 month after ALRP (p = 0.262). There was a statistically significant increase in LD after ALRP compared to before ALRP, but it decreased after 1 month. There was an increase in the coefficient of variance (CV) after ALRP compared to before ALRP but it was not statistically significant (p = 0.188). There was no statistically significant difference in CV between before ALRP and 1 month after ALRP (p = 1.000). There was no statistically significant difference in the cell density, the hexagonality percentage between before ALRP, after ALRP, and 1 month after ALRP (p = 0.993, and 0.863, respectively). ALRP may affect the lens densitometry temporarily during the procedure. Thermal damage may be the reason for increased lens densitometry.