The present study was conducted to investigate the morphological features of the retinal photoreceptors of two goldfish strains: the black moor and fantail, using light (LM) and transmission electron microscopy (TEM) to illustrate their visual adaptation to the fish's lifestyle. Both the fantail and black moor have been DNA barcoded using COI partial sequence and proved to belong to Carassius auratus species. The newly obtained sequences were banked to the gene bank and given accession numbers: PP106365 and PP106366, respectively. Histologically, both strains had the same retinal characteristics as all vertebrates. The retina consists of a pigmented epithelium on the exterior and a neural layer with many layers within. Both strains possessed cone photoreceptor cells exclusively, which suggested that their visual adaptation was related to their watery habitat. Significant changes in the arrangement of photoreceptors and the thickness of the retinal layer between both strains imply that visual acuity and color perception may differ due to their adaptations to distinct ecological niches.  Through TEM, the cone cells were observed, providing comprehensive information about their structural specializations that allow them to efficiently absorb and convert light. Our research highlights species-specific discrepancies in the thickness of different retinal layers, hence emphasizing the existence of unique visual processing capacities. The present work enhanced the understanding of Carassius auratus' evolutionary biology and the intricate nature of visual adaptations, which are crucial for understanding fish vision and the evolutionary forces shaping their sensory systems in their surroundings.