Question: What is (are) Blue cone monochromatism ?
Answer: Blue cone monochromatism is an inherited X-linked vision disorder. In this condition both red and green cone sensitivities are absent, however rod function and blue cone sensitivities are present. Signs and symptoms include severely reduced visual acuity (clearnes), eccentric fixation, infantile nystagmus that decreases with age, no obvious retinal abnormalities, and poor or no color discrimination.
Source: GARD

Question: What are the symptoms of Blue cone monochromatism ?
Answer: What are the signs and symptoms of Blue cone monochromatism? The Human Phenotype Ontology provides the following list of signs and symptoms for Blue cone monochromatism. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Nystagmus 75% Abnormal electroretinogram 7.5% Abnormality of color vision 7.5% Abnormality of macular pigmentation 7.5% Abnormality of retinal pigmentation 7.5% Corneal dystrophy 7.5% Photophobia 7.5% Visual impairment 7.5% Blue cone monochromacy - Myopia - Reduced visual acuity - X-linked recessive inheritance - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD