Low vision is a term that denotes a level of visual acuity that is 20/70 or worse (perfect visual acuity is 20/20) and cannot be fully corrected with conventional glasses or contact lenses. A person with low vision has much useful sight. However, low vision usually interferes with the performance of daily activities, such as reading and driving. A person with low vision may not recognize images at a distance or be able to differentiate colors of similar tones.