People with complete achromatopsia have difficulty in seeing detail (lines 2–3) - AQA - A-Level Biology - Question 10 - 2018 - Paper 1

Individuals with complete achromatopsia lack functional cones in their retinas, which are the photoreceptors responsible for color vision and detailed visual acuity. Without these cones, vision is primarily reliant on rods, which are less sensitive to light detail. As a result, this leads to a significant impairment in perceiving fine detail and colors, making it challenging to perceive the visual world in high resolution.