One single family of corneal lattice dystrophy was examined and interviewed to elucidate the variety of clinical manifestations, factors associated with visual impairment, and the impact on the patient's quality of life. Forty-three out of 88 family members (48.9%) were affected. The inheritance pattern was autosomal dominant. Corneal haze grading from 1 to 4 was 5.3 per cent, 26.3 per cent, 43.4 per cent, and 25 per cent respectively. Surface irregularity grading from 1 to 4 was 18.4 per cent, 39.5 per cent, 32.9 per cent, and 9.2 per cent respectively. Forty-five per cent of the patients had VA < or = 20/200. Corneal haziness, irregularity, corneal erosion and disease duration were significantly related to visual impairment (p < 0.05). This disturbed the patient's activities such as reading (79.1%), working (62.8%) and daily life (69.8%). Corneal lattice dystrophy within the same family may present with different manifestations depending on the severity and duration of the disease and might be misdiagnosed. Inadequate knowledge among patients was susceptible to the high prevalence of the disease leading to impaired quality of life.