Light affects plant growth and fruit quality. Local pear genotypes from Muş region (Eastern Anatolia, Türkiye) have not been evaluated for their responses to contrasting light conditions. This study compared 13 local genotypes and 4 standard cultivars under natural sun and shade. Under shade, leaf area increased by 9.8–11.2%, highest in Mor Armut (55.56 cm²), Abbasi (49.12 cm²) and Santa Maria (46.66 cm²). Şuti and Pamukhala increased petiole angle. Stomatal density was higher under sun (Abbasi: 422, Mihrani: 402 mm⁻²) and decreased by 17.3% under shade. Güz‑1 maintained stomatal density but increased stomatal length (24.95→29.58 µm) and pore length (18.04→21.74 µm). SPAD showed strong genotype × light interaction: Abbasi increased SPAD under shade (52.08→56.00), whereas Pamukhala, Mihrani and Yaz Armudu decreased. Fruit weight was highest in Paşa‑2 (274.36 g), SSC in Güz‑1 (19.8%) and Mor Armut (19.7%), and flesh firmness in Van Armudu (11.01 kg cm⁻²) and Güz‑1 (9.98 kg cm⁻²). Pearson correlations revealed very strong positive relationships between leaf area and width (r=0.933) and among fruit dimensions (r>0.88) under sun; a strong negative correlation between acidity and pH (r=-0.813) under shade. PCA explained 39.4% (sun) and 38.2% (shade) of variance. Hierarchical clustering showed two main clusters under both conditions. Local genotypes (especially Abbasi, Mor Armut, Güz‑1, Paşa‑2) exhibited higher phenotypic plasticity and three shade adaptation strategies: increasing leaf area, increasing stomatal/pore dimensions, and reducing stomatal density while altering petiole angle. These findings highlight the value of Muş pear genetic resources for breeding and climate adaptation.