Presbyopia is diagnosed by a basic eye exam, which includes a refraction assessment and an eye health exam. A refraction assessment determines if you have nearsightedness or farsightedness, astigmatism, or presbyopia. Your doctor may use various instruments and ask you to look through several lenses to test your distance and close-up vision.
https://www.mayoclinic.org/diseases-conditions/presbyopia/diagnosis-treatment/drc-20363329

