Do you wear Progressive Eyeglasses? Ever wonder what are the factors that are considered when creating one? These facts could serve you well especially when getting your prescription regarding corrective eyewear.
What is Pupillary Distance?
Pupillary Distance (PD) is the distance (in millimeters) between the centers of the pupils in each eye. This specific way of measuring is employed when getting ready to create prescription eyeglasses. Placing lenses accurately in relative to the center of the pupils is mainly critical for higher powered lenses due to the position of the optical center of the lenses. A PD measurement makes sure that the center of the lenses line up with the center of your pupil. The Pupillary Distance needs to be measured first before your prescription lenses are cut into the form of your frame. This kind of measurement is utilized so that the optical center of each lens can be lined up with your pupils in order to give maximum visual quality.
Progressive Eyeglasses was a huge leap forward in terms of advances in corrective eyewear. Three focal distance areas are combined into a single lens, resulting in the following: The upper part of the lens is focused in viewing objects at a distance, the center part is for medium-distance viewing capacity (eg, scanning book titles on library shelves ), and the lower area of the lens is optimized for closer viewing distances, (eg, reading text on the computer monitor). Through this type of multi-focal lens, the user is provided with a more realistic viewing experience since it gives more power to view different types of distances seamlessly. For example, a person standing across the room can be clearly seen when gazed at, moving your head a bit afterward to check what your typing on the PC is a simple task, and then tilting your head down to continue your reading is as easy as 1-2-3. This results to a smooth and seamless transition of lens powers, enabling the user to change focus from different viewing distances much more faster and comfortable.
Now that we know the idea behind Progressive Eyeglasses, it's now time to incorporate it into our knowledge of Pupillary Distance mentioned a while back. You see, when your optometrist or ophthalmologist assesses your eye status before they create prescription glasses, the PD in one of the most important factor they first consider. A “path” of optimum vision can be traced downwards each progressive lens. The eye doctor will take accurate measurements of your eyes and then of the eyeglass frames in order to align the “path” in the perfect location so your eyes can make use of the different lens powers for easy viewing at all distances.
When fitted for the first time with your new progressive glasses, a time period of adaptation should be expected which could range from a few minutes to a couple of days. This is due to the fact that the lens powers that were blended causes minor aberrations on the peripheral area of the lenses. So do not worry too much during this transition phase, just give it a few days or weeks and these problems will go away.