This completely free app (no ads) is intended for family members, friends, teachers and others to better understand the impact Blue Cone Monochromacy (BCM) has on color vision. BCM is a rare genetic condition the app developer has that causes severe colorblindness along with poor acuity (detail vision) and other vision problems. The app removes red from the image which leaves blue and green intact. This matches reasonably with BCM color vision in that with BCM S-cones which are sensitive to blue and rods which are sensitive to medium wavelengths (greens) are both active in medium bright indoor lighting. For normal vision rods are mainly used for night vision but for a poorly understood reason are somehow suppressed in brighter light. Normal vision is sensitive to red, green, and blue (trichromatic vision). With BCM vision is largely sensitive only to green and blue (dichromatic 2 color vision). For more details see the support web page.
