"PL" or "Pl" means "Plano." The easy way to understand this is to just think of "zero" when you encounter it in a glasses prescription or in any other assessment of refractive error and vision. Historically, lens grinders would have a blank piece of glass with...
What a great question! Why didn't all the nearsighted cavemen, with blurry distance vision, get eaten by saber-tooth tigers and other predators before they could reproduce? The answer is most likely that these conditions are largely acquired rather than purely genetic. Once a controversial theory, there...
A dilemma, isn't it? The one good thing about being nearsighted is that you can still see up close (at least without your glasses on) when you become Presbyopic in middle age. The reason for this is that with a myopic (nearsighted) eye being larger than normal, your default focal point...
The most common eye problems in America are refractive disorders. That means nearsightedness, farsightedness and astigmatism combined are to blame for most of the country's diminished vision. So what are these refractive errors? How can you prevent them? How do people live fulfilling lives with...
As you age, the normally clear lens of your eye can become more opaque in some spots; this is known as cataracts and can produce vision that is blurry or foggy. Cataracts often develop slowly and imperceptibly, but eventually produce symptoms that become difficult to ignore. Cataract eye surgery...
How can we convert 20/20 feet to 6/6 visual acuity in a Snellen chart? These are just the different measurement conventions of the U.S. (feet and inches) and the rest of the world using the metric system (meters and cm.). So the answer is “they are...
Why do doctors put a lens in the eye after removing a cataract? Is it possible to remove a cataract without surgery? What are the chances of having a cataract again, after surgery? This question shows how we eye doctors could be doing a much better...
No. Presbyopia is a problem with near vision caused by the age-related hardening of the natural lens of the eye such that the surrounding muscle can no longer easily squeeze it into a different shape for focusing up close. When this hardening gets more advanced, the lens also...
Since a cataract is a cloudy natural lens, every cataract operation involves replacing it with a new, artificial lens implant: an IOL (Intraocular Lens Implant). The cost of the "entry level" IOL is included in the packaged fee that Medicare pays to the ambulatory surgical center (ASC) or...
It depends on what you mean by "astigmatism" and how bad it is. "Astigmatism" means the eye is not regular and equal in its focusing ability for every ray of light entering through the pupil. There is "regular" and what used to be called "irregular" astigmatism...
