What does albinism refer to in terms of skin pigmentation?

Albinism refers to a genetic condition characterized by the absence or significant reduction of melanin pigment in the skin, hair, and eyes. Melanin is the pigment responsible for giving color to the skin, and in individuals with albinism, the lack of melanin results in very light skin and hair, as well as potential problems with vision and sensitivity to sunlight. This absence of pigment is due to a mutation in the genes that are responsible for the production of melanin, leading to the observable traits associated with albinism.

The other options do not accurately describe the condition: excess melanin indicates hyperpigmentation, skin lesions refer to abnormal growths or changes in the skin, and fibrous tissue relates to connective tissue rather than pigmentation. Thus, the emphasis on the absence of melanin pigment directly aligns with the defining characteristics of albinism.