What is Ishihara

It is important to screen for acquired or hereditary color vision defects as early as possible. Color vision is a critical part of the early learning experience, and children who have color deficiencies may have difficulties compared to their peers if there is color-based schoolwork. It becomes important for career interests/goals for older children as some jobs may require normal color vision. Hereditary red-green deficiencies are X-linked and therefore affect approximately 8% of males and less than 1% of females. Acquired color vision defects and blue-yellow defects are rare in the pediatric population; therefore, these conditions will be discussed minimally in this chapter. Infants are able to discern color by 2-3 months of age, but accurate color naming may not develop until 4-6 years of age. Screening tests are sensitive, fast, and easy to administer. If a deficiency is suspected through screening, further testing must be evaluated in order to determine the type and severity of the color vision defect. Color vision is typically tested starting at age 3 years and up.