Inclusion Criteria:  - Objective and subjective evidence of presbyopia.  Exclusion Criteria:  Corneal abnormalities (including keratoconus, corneal scar, Fuchs' endothelial dystrophy, guttata, or edema) in either eye that are likely to interfere with visual acuity. Narrow iridocorneal angles (Shaffer grade <=2 or lower on gonioscopy examination), history of angle-closure glaucoma, or previous iridotomy. Diagnosis of any type of glaucoma or ocular hypertension. History of cataract surgery, phakic intraocular lens surgery, corneal inlay surgery, radial keratotomy, or any intraocular surgery. Use of temporary or permanent punctal plugs or history of punctal cautery in one or both eyes.