We consider research results on the effect of the active medium temperature, which varies with the operation of semiconductor and solid-state (DPSS) lasers of the visible range, on the output spectral characteristics. The paper presents the study results of the spectral-optical radiation parameters of semiconductor lasers, their coherence lengths, and the dependence of the spectral maximum position on temperature. This study is necessary for selection of the most optimal laser, which in the future is planned to be used in medical ophthalmologic diagnostics. The experiment was carried out by solid-state (DPSS) and semiconductor laser modules based on a laser diode. Spectral dependences on the active medium temperature of lasers were obtained, ranging from 300 to 370 K. The spectra were recorded with the use of an automated spectral complex based on the MDR-23 monochromator. We show determination possibility of the internal stabilization damage of laser modules without mechanical intervention but only by applying their spectral characteristics. The obtained data give the possibility to take into account the temperature characteristics and perform further optimization for parameters of such lasers