As people age, the lens in their eye loses elasticity, making it difficult to focus on nearby objects, such as a newspaper or book. The condition is called presbyopia, and it affects millions of people. It usually begins around the age of 45 and progresses until 65. To adapt to presbyopia, people often use reading glasses.

The FDA recently approved a new drug called Vuity to treat presbyopia. Vuity is a once-daily eye drop that contains pilocarpine, a cholinergic muscarinic agonist. Pilocarpine causes pupillary constriction and ciliary muscle contraction, actions that facilitate near vision. In a trial that enrolled 427 patients with presbyopia, near vision improved (defined as gaining 3 or more lines in near visual acuity without losing more than 1 line of distance acuity at 3 hours after dosing) in 26% of Vuity-treated patients and 11% of placebo-treated patients. Maximal benefit occurred 1 hour after dosing, after which the effect steadily declined and became nonsignificant 6 hours post-dose. Side effects occurring in more than 5% of patients included headache and conjunctival hyperemia.

Patients prescribed Vuity should be aware that their vision in poor lighting may be impaired because pilocarpine inhibits pupillary dilation. Contact lens wearers should remove their contacts before instilling the drops and wait at least 10 minutes before reinserting them. The only contraindication is hypersensitivity to the drops.

In summary, around 30% of Vuity users will gain 3 or more lines of acuity in their near vision. Smaller improvements may also be meaningful to some people. Cash-pay prices for Vuity are around $80 for a 2.5 ml bottle, which provides about 25 days of treatment. Interested patients will have to try Vuity and see if the pros outweigh the cons. It's hard to imagine an eye drop that works for less than six hours and can impair night and distance vision would be preferable to slipping reading glasses on and off.