The maximum amount of accommodation that can be relaxed while maintaining clear, single binocular vision at a fixed distance, typically 40 cm. It is measured clinically by adding plus lenses binocularly until the patient reports the first sustained blur. NRA assesses the flexibility of the accommodative system relative to vergence demand. Low NRA findings may indicate accommodative excess or latent hyperopia, while high values suggest uncorrected hyperopia or over-minused refraction.