Rather than a visual defect, presbyopia is a hardening of the lens of the eye over time. As the lens becomes less elastic, the ability to focus on nearby objects diminishes. It mostly affects the over-40s, and tends to stabilize after the age of 60.
You'll notice if you have it, because the ability to see close-up objects gets progressively worse.
Reading glasses, bifocals, varifocals or lens implants may be needed. A chat with your optometerist will help you to find the right lens, depending on your lifestyle and severity of the condition, this may be simple reading glasses, mid-distance lenses or progressive lenses for a more optimum solution.