Abstract <p>Artificial light pollution, an escalating environmental issue, significantly disrupts natural nighttime light conditions. This research investigates the impact of artificial light at night (ALAN) on <i>Solanum melongena</i> L., focusing on photosynthesis, biochemical profiles, and ultrastructural changes. The study aims to elucidate how continuous light exposure at night affects plant physiology and metabolic processes. Plants were grown under two light conditions: natural sunlight followed by complete darkness (S1 plants, control) and ALAN in addition to natural sunlight (S2 plants), with key parameters measured, including growth metrics, photosynthetic rates, biochemical profiles, and ultrastructural changes assessed via microscopy. Results indicated that ALAN exposure led to increased shoot and root lengths, higher biomass, and larger leaf area compared to controls. Photosynthetic rates and stomatal conductance were found to be enhanced under ALAN, but internal CO₂ concentrations and transpiration rates showed significant alterations. Biochemically, ALAN-treated plants exhibited higher chlorophyll content, increased antioxidant enzyme activities, and elevated flavonoid and protein levels. Ultrastructural analysis revealed significant changes in chloroplast integrity, nuclear function, and mitochondrial activity under ALAN conditions. The study concludes that ALAN significantly affects the physiological, biochemical, and ultrastructural dynamics of <i>S. melongena</i>, highlighting the need for strategies to mitigate light pollution and preserve plant health and ecosystem balance.</p>