What Is 20/20 Vision?

The term “20/20” and similar fractions (such as 20/40, 20/60, etc.) are visual acuity measurements. They also are called Snellen fractions, named after Herman Snellen, the Dutch ophthalmologist who developed this measurement system in 1862. In the Snellen visual acuity system, the top number of the Snellen fraction is the viewing distance between the patient and the eye chart.

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At this testing distance, the size of the letters on one of the smaller lines near the bottom of the eye chart has been standardized to correspond to “normal” visual acuity — this is the “20/20” line. If you can identify the letters on this line but none smaller, you have normal (20/20) visual acuit.FOR MORE

Aspheric IOLs

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Traditional intraocular lenses have a spherical optical design, meaning the front surface is uniformly curved from the center of the lens to its periphery. Though a spherical IOL is relatively easy to manufacture, this design does not mimic the shape of the natural lens inside the eye, which varies in curvature from center to periphery. In other words, the eye’s natural lens is aspheric (“not spherical”).READ MORE

Can LASIK Hurt Night Vision?

LASIK surgery has been proven safe and effective for the correction of nearsightedness, farsightedness and/or astigmatism, and most people are very pleased with their LASIK results.

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In fact, many people who choose to have LASIK surgery report their night vision after surgery is noticeably sharper than it was with eyeglasses or contact lenses prior to surgery.

In 2014, the Food and Drug Administration (FDA), National Eye Institute (NEI) and Department of Defense released results of their jointly sponsored LASIK Quality of Life Collaboration Project, which evaluated LASIK risks and complications, based on patient-reported outcomes via a standardized survey.READ MORE

Various tests for detecting dry eyes

Schirmer test : A thin strip of paper placed under the lower eyelid to measure tear production.

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Tear breakup time : Placement of a small amount of dye on the eye’s surface to monitor how tears are distributed and when they “break up” on the eye’s surface.
Imaging : Keratometers or other instruments that provide a view of the tear film without touching the eye’s surface.
MMP-9 Testing : To perform this is a painless test, your doctor will collect a small sample of your tears from the inside of your bottom lid. Within minutes, you’ll know whether you have high levels of a protein that can cause you to struggle with inflammatory dry eye after LASIK.

What Is Overflow Tearing?

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Overflow tearing, a common birth condition in infants, occurs due to a narrowing or blocking of the canaliculus, a part of the nasal lacrimal drainage system. The blocked system can spontaneously open within a few months of birth, or it can be surgically opened. Overflow tearing can also occur when the child’s eyelashes stick together after sleep, a situation that can cause one or both eyes to become chronically infected; or when environmental elements irritate the eye.FOR MORE

Treatment of Glaucoma

The treatment for glaucoma depends upon the nature and severity of each case. In general, glaucoma cannot be cured, but it can be controlled. Eye drops, pills, laser procedures, and surgical operations are used to prevent or slow further damage from occurring.

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With any type of glaucoma, regular eye examinations are very important to detect progression and to prevent vision loss. Because glaucoma can worsen without your being aware of it, your treatment will likely need to be changed over time to achieve a lower “target eye pressure.”FOR MORE