trifocal
Three-distance vision aid
Trifocal describes lenses with three distinct focal lengths—typically for near, intermediate, and distance vision.
Most often encountered as the plural noun trifocals, referring to eyeglasses with such lenses: She switched from bifocals to trifocals when computer work strained her eyes.
The middle segment addresses the gap bifocals leave for mid-range tasks.
Corrective eyewear worn daily
- glassesCorrective eyewear or tumblers
- eyeglassesCorrective lenses worn
- framesRigid enclosing structures
- opticianOne who dispenses corrective lenses
fitting · temple · bridge · nose pads · plastic frames · designer frames · prescription glasses · readers
Social reform advocates
- varifocalLens with gradual power change
- presbyopiaAge-related near vision loss
- prescriptionMedical dispensing authorization
- correctionFixing of mistakes
segment · near · intermediate · distance · optometry · polycarbonate · anti-reflective · coating
Ability to see nearby
- distance visionSeeing objects far away
- clarityState of being understandable
- depth perceptionGauging object distance visually
- visual acuityClarity of eyesight
sight · accommodation · eye exam · optometrist · ophthalmologist · refraction
spectacles
Corrective eyewear worn daily
- glassesCorrective eyewear or tumblers
- eyeglassesCorrective lenses worn
- framesRigid enclosing structures
optician · fitting · temple · bridge · nose pads · plastic frames · designer frames · prescription glasses · readers
progressives
Social reform advocates
- varifocalLens with gradual power change
- presbyopiaAge-related near vision loss
- prescriptionMedical dispensing authorization
correction · segment · near · intermediate · distance · optometry · polycarbonate · anti-reflective · coating · optical
near vision
Ability to see nearby
- distance visionSeeing objects far away
- clarityState of being understandable
- depth perceptionGauging object distance visually
visual acuity · sight · accommodation · eye exam · optometrist · ophthalmologist · refraction
- eyeglass lensesprogressive, progressive lenses, progressives, single vision, varifocal
- lenseszoom lens, prime lens, progressive, single vision, camera lens
- opticslens, lenses, mirror, mirrors, prism