Ads
related to: do my glasses show pd number on my computer page 12 of 2017
Search results
Results from the WOW.Com Content Network
PD or IPD Pupillary Distance or Interpupillary Distance, respectively. It is the distance between pupil centers. BVD Back vertex distance is the distance between the back of the spectacle lens and the front of the cornea (the front surface of the eye). This is significant in higher prescriptions (usually beyond ±4.00D) as slight changes in the ...
Distance PD is the separation between the visual axes of the eyes in their primary position, as the subject fixates on an infinitely distant object. [2] Near PD is the separation between the visual axes of the eyes, at the plane of the spectacle lenses, as the subject fixates on a near object at the intended working distance. [3]
These instruments are most commonly used for fitting glasses (i.e., center the lenses on the visual axes). However, they may also be used to verify a PD measurements taken with a PD stick. Since these instruments do not measure any actual pupil parameters (e.g., size, symmetry, reflex, etc.), they do not fall under the medical device definition ...
In glasses with powers beyond ±4.00D, the vertex distance can affect the effective power of the glasses. [4] A shorter vertex distance can expand the field of view, but if the vertex distance is too small, the eyelashes will come into contact with the back of the lens, smudging the lens and causing annoyance for the wearer.
Zenni Optical mail order. Zenni Optical was founded in 2003 by Tibor Laczay and Julia Zhen. [1] [2] Before being renamed to Zenni Optical when it began offering $7 and $8 glasses, the company was named 19dollareyeglasses.com. [3] [4] [5] Around 2014, co-founder Zhen acquired the building occupied by the Marin Independent Journal to house Zenni. [6]
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Ads
related to: do my glasses show pd number on my computer page 12 of 2017