We are experiencing technical difficulties with our phone messaging. If you are unable to leave a voice message, please submit through our website form or call back again at another time until you get through. We apologize for the inconvenience and hope to have this resolved soon. 

  • How to Read your Eye Prescription and What it Means

    Learn the Ways to Read Eye Prescription at Gerstein Eye Institute

    You’ve visited the eye doctor and obtained a prescription for eyeglasses or contacts, but when you look at your prescription, all you see is letters and numbers. For the uninitiated, an eye prescription can be confusing. It’s actually not too complicated, once you know what those letters and numbers mean.

    The numbers on your prescription will be listed under headings listed as OS and OD. Those headings are Latin abbreviations: OS means oculus sinister, which refers to the left eye, and OD means oculus dexterous, the right eye. Some prescriptions will also have the abbreviation OU, which stands for oculus uterque and pertains to both eyes. You might also see the letter D, which stands for diopters, the unit doctors use to measure

    You’ll also notice that in front of the numbers that follow there are plus or minus signs. A plus sign (+) indicates farsightedness, while a minus sign (-) means that you’re nearsighted. How nearsighted or farsighted you are is indicated by the numbers: as a rule, the further away the number is from zero, the worse your vision and the higher your requirement for vision correction.

    For instance, a prescription that says -1.00 indicates one diopter of nearsightedness, which is a fairly mild level of nearsightedness. Someone with a higher level of nearsightedness, perhaps -4.25, would require a much stronger corrective lens, which would be thicker. Farsightedness works the same way, with a +5.00 prescription being much stronger than, for instance, a +1.00.

    Are there more letters and numbers on your prescription? If you have astigmatism, there should be three sets. They will generally be written as S x C x Axis. S means spherical, and it will be the number discussed earlier, describing farsightedness or nearsightedness. C is for cylinder, which is referring to the astigmatism. This can be a negative or positive number, showing in diopters your degree of astigmatism. The larger the number, the more severe the astigmatism. The number for the Axis is expressed in degrees and will be somewhere between 0 and 180. Astigmatism is a curvature of the cornea, and the Axis is the number that indicates that curvature’s orientation.

    If your prescription says ADD, that abbreviation is referring to the magnifying power for your reading, progressive or bifocal lenses. The same number will apply to both eyes. If you see the abbreviation PD, that stands for Pupillary Distance, the distance between the centers of your two pupils.

    On a contact lens prescription, you’ll find the same listing of power under OD and OS, and some of the same information you’d see on an eyeglasses prescription. In addition, however, a contact lens prescription will include the prescribed brand, as well as numbers following the abbreviations BC and Dia. BC means Base Curve, Dia stands for diameter, and these two measurements together ensure the proper fit on your eye’s surface.

    If you are looking for an eye doctor, the Gerstein Eye Institute in Chicago can help. Since 1968, the Gerstein Eye Institute has been providing exceptional ophthalmologic care to patients in the Chicago area. With decades of experience in ophthalmology, our certified professional staff members work hard to provide the kind of personalized care that keeps patients coming back year after year, eventually entrusting the eye health of their children and grandchildren to us as well. To schedule an appointment, call us at (773) 973-3223 or contact us through our website.

  • How Does Bright Light Affect Your Vision?

    Bright light affects for your vision in Chicago

    The iris serves as your eye’s main defense against bright light. This is the colored part of your eye responsible for reducing and enlarging the size of your pupil. When intense light rays reach your eye, the iris responds by constricting the pupil, thus protecting the retina and helping it process the incoming image better. The opposite occurs in low light when the iris dilates the pupil to allow as much light in as possible.

    Can Bright Light Damage Your Vision?

    In short, yes, staring at bright lights can damage your eyes. When the retina’s light-sensing cells become over-stimulated from looking at a bright light, they release massive amounts of signaling chemicals, injuring the back of the eye as a result.

    The sun shines with such intensity that staring directly at it for just a few seconds can cause permanent retinal damage. Chronic exposure to UV rays over many weeks, months or years can also harm the macula, cornea and lens. A damaged macula leads to macular degeneration. A “sunburned” cornea can cause blurry vision and loss of eyesight. A damaged lens may develop a cataract, or clouding of the lens that blurs vision.

    Blue light, even at moderate intensity levels, can damage your retinas slowly over time. Blue light has shorter wavelengths than warmer light, so it has more energy. Prolonged exposure may increase the risk of age-related macular degeneration (AMD). Sunlight is the most prominent source of blue light, but other examples include fluorescent lights, LEDs, TVs, computer monitors and Smartphone screens.

    How to Treat and Prevent Eye Problems from Bright Light

    Protect your vision with these tips:

    • Choose glasses with anti-reflective lenses to reduce glare from bright lights.
    • Wear dark-tinted sunglasses and a brimmed hat while outside. Polarized sunglasses with UV protection further shield your eyes from the effects of blue light and ultraviolet rays.
    • Decrease daily screen time and take frequent breaks to rest your eyes.
    • Turn on your computer’s “night light” feature to decrease the amount of blue light the screen emits.
    • Wear blue-blocking computer glasses with yellow-tinted lenses that ease digital eyestrain.
    • Choose CFLs and LEDs that emit “warm” light.
    • If you require cataract surgery, seek blue-blocking intraocular lens (IOL) implants to protect your retinas the same way sunglasses do.

    If you’re experiencing any vision problems or discomfort after exposure to bright light, visit Gerstein Eye Institute in Chicago, IL for an evaluation. Our commitment to helping patients protect their vision dates back to 1968. For more information, or to schedule an eye appointment, please contact us at 773.596.9545 today.

  • Help Protect Your Vision with Regular Eye Exams

    Just like physical exams and dental check-ups, eye exams from an ophthalmologist are an essential part of a complete preventive wellness plan. If it’s been longer than a year or two since you’ve visited an optical center near Chicago, it’s time to make an appointment. Even if you aren’t experiencing any vision problems, it’s important to have regular eye exams . You can learn why when you watch this animation.

    It explains that the symptoms of serious eye diseases aren’t always detectable right away. You might not experience dark spots or cloudy vision until diabetic retinopathy and cataracts are already in the advanced stages—but an eye doctor can. He or she will let you know how often you should get an exam, based on your family health history, personal health history, and age. And if you do experience any sudden changes in your vision, get to an optical center right away.

  • Cataracts 101

    Cataracts are an eye condition that typically causes blurry, dim, or cloudy vision. If your ophthalmologist has diagnosed you with this disease and recommended that you consider getting intraocular implants through cataract surgery near Chicago , then watch this video to understand the basics of this condition.

    Cataracts are a common eye problem that affects millions of individuals as they age, and it develops when a person’s eye lens, which is normally clear, becomes cloudy. This condition is typically the result of age-related changes that affect the eye and is seen most commonly in individuals over age 60. This condition cannot be reversed, but an ophthalmologist can remove cataracts and restore vision in most cases.

  • Summertime Eye Safety Tips

    Regular visits to your ophthalmologist in Chicago can help you protect your vision and eye health. However, no one wants to see an eye doctor because of an injury. To help keep your eyes protected from harm this season, read on for some helpful summertime eye safety tips. Summertime Eye Safety Tips

    Wear Goggles

    Summer equals swim season, and many people spend hours at a time in the pool while exercising, playing, or relaxing. However, chlorine can affect the health of your eyes, so you can benefit from protecting them from the chemicals in pool water. To avoid blurry vision and gritty-feeling eyes, wear goggles while you swim and rinse your eyes with fresh water afterward.

    Carry Eyedrops

    Hot and arid environments can affect your tear film and leave your eyes feeling dry and gritty. Because of this, if you’ll be spending time in a dry or windy location this summer, then you should take precautions against dry eye. You can do this by carrying artificial tears and wearing wraparound sunglasses.

    Prioritize Safety

    Many eye injuries happen around the home, so you shouldn’t overlook the importance of eye safety as you work through that summertime to-do list. Whether you’re beginning a new DIY project or trimming trees, you can practice good eye care by wearing proper protective eyewear.

    Wear Sunglasses

    Did you know that your eyes are vulnerable to damage from the sun, just like your skin? Sometimes called “sunburn of the eye,” photokeratitis is a painful condition that can be caused by sunlight that bounces off highly reflective surfaces, such as sand and water. To help avoid the redness, pain, and blurry vision associated with photokeratitis, ophthalmologists recommend that you wear sunglasses with 100% UV protection and a wide-brimmed hat, if possible.

    Quit Smoking

    Quitting smoking can be a great addition to your list of summer health goals. Smoking is a risk factor for many health conditions, including some that affect the eyes, such as macular degeneration and cataracts. Reduce your risk of eye disease and other health issues by quitting smoking this season.

  • Understanding Low Vision

    For some people, corrective eyewear and eye surgery cannot improve their vision. If someone you know has an eyesight problem that cannot be fixed through vision correction options like LASIK , contact lenses, or eyeglasses, then his ophthalmologist in Chicago may diagnose him with low vision. Watch this video to learn more about what it means to have and live with low vision.

    Having low vision can make it difficult to complete everyday tasks like driving, shopping, reading, watching TV, and recognizing faces. Because there are many causes of low vision, people can be affected by low vision in various ways. While one person’s condition may affect her central vision or contrast sensitivity, another person’s may impact his depth perception or peripheral vision.

  • What Are the Risk Factors for Glaucoma?

    When was the last time you visited your optical center in Chicago to have your eyes tested for glaucoma by an eye doctor? If it’s been more than a couple of years, then you could be overdue for a screening. Read on to learn what puts you at greater risk for developing glaucoma. Glaucoma Risk Factors


    Individuals over 40 are at a higher risk for both open-angle glaucoma (OAG) and closed-angle glaucoma (CAG), and your age impacts how frequently you should be seeing an eye doctor for testing. People under age 40 should visit an eye care professional every 2 to 4 years. From ages 40 to 54, see your eye doctor every 1 to 3 years. Individuals who are between ages 55 and 64 should have their eyes tested every 1 to 2 years. Once reaching 65 years of age, people should visit their eye doctor once every 6 to 12 months.


    Race has been linked to different types of glaucoma. People of African descent are at a higher risk for developing OAG than Caucasians, and people with East Asian ancestry are more likely to suffer from CAG than other individuals. Also, Hispanics in older age groups are at a greater risk for glaucoma. If you fall into one of these high-risk groups, then consider seeing your eye doctor more frequently.

    Family History

    OAG is the most common form of glaucoma, and both it and CAG are hereditary conditions. This means that if you have immediate family members who suffer from glaucoma, that you should be seeing an eye doctor for testing more frequently than you would otherwise because you have a much greater risk of developing the disease.

    Other Factors

    There are several other factors that can increase your risk for open-angle glaucoma which include having high pressure in the eyes, having diabetes, and having prior loss of vision due to glaucoma. Additional risk factors for closed-angle glaucoma include being female, having farsightedness, and having CAG in one eye. If any of these risk factors apply to you, then speak with your ophthalmologist about how often you should have your eyes checked for glaucoma.

  • Keeping Your Eyes Safe This New Year’s Eve

    Your ophthalmologist near Chicago will tell you that the holiday season can be particularly hazardous for the health of your eyes. To help avoid an accident, continue reading to learn how to practice good eye care this New Year’s Eve. 2017 Eye Care Tips


    If you’re like most people, then you intend to ring in the new year with a champagne toast during your holiday party. To make a great impression on your guests, learn how to open a champagne bottle like a pro, something which does not involve flying corks. The uncontrolled release of a cork from a bottle of sparkling wine or champagne can reach up to 50mph, making it a serious eye hazard, according to eye doctors. You can help protect everyone’s eyes at your party by learning to safely open champagne.


    A frequently underestimated New Year’s Eve tradition, the use of sparklers is one of the leading fireworks-related causes of emergency trips to an eye doctor. For this reason, their use should be approached with the same level of caution as fireworks. To use sparklers safely this holiday, only light them outdoors, light only one at a time, point sparklers away from your face and those of others, and always keep a bucket of water nearby. As for fireworks, do not touch unexploded fireworks, always wear protective gear when handling fireworks, and respect all safety barriers at fireworks shows.


    For many people, a New Year’s Eve party is lacking if there aren’t party poppers involved. If you plan to celebrate with party poppers this holiday, keep in mind that they can cause eye injuries if they aren’t used with caution. First, always point party poppers away from your face and those of others. Second, avoid trying to fix poppers that turn out to be duds because there is a chance that they will explode in your face while you’re working on them. Finally, never allow children to use party poppers alone and be sure to instruct them on their safe and proper use.

  • Cosmetic Lenses and Your Eye Health

    Are you looking for cosmetic contact lenses in Chicago to complete your Halloween costume? If so, you’re not alone. Cosmetic lenses are a popular costume accessory that can be safe and fun. However, there are some important facts that you should know about when it comes to these contact lenses and your eye health. Cosmetic lenses in Chicago

    What are cosmetic lenses?

    Designed to change the appearance of a person’s iris in some way, many people enjoy wearing cosmetic lenses day-to-day and for special occasions. For example, cosmetic lenses can make a person’s green eyes look a bit greener, make the entire iris appear black, or make the pupil appear the same shape as a cat’s. However, the most important thing that you should know about cosmetic lenses is that they are medical devices and should be approached in the same way that a pair of corrective lenses would be approached.

    How do I get cosmetic lenses?

    Because cosmetic lenses qualify as medical devices, they require FDA approval and an up-to-date contact lens prescription from an eye doctor to be sold in the United States. This means that even if you do not need prescription eyeglasses or contact lenses to see well, that you will need to visit an optical center to get a prescription if you want to wear your cosmetic lenses safely. Once you have your contact lens eye prescription, you can purchase the contacts of your choice from an FDA approved company.

    Why are cosmetic lenses considered medical devices?

    In the past, you could find contact lenses being sold as “one size fits all” in costume and novelty stores. The problem with this is that eyes are not the same shape from person to person, and even a single individual can have eyes that are not identical in shape. When you wear contact lenses that do not fit your eyes, this can lead to infections and permanent eye damage. For these reasons, you must purchase and care for cosmetic lenses in the same way you would a prescription pair.

  • Tips for Preventing Eye Injuries Around the Home

    With the growing popularity of DIY projects and home improvement repairs, it may come as no surprise that eye injuries that occur at home are on the rise. As part of your family’s ongoing eye care near Chicago, use the following tips to help prevent eye injuries around your home. Prevent Eye Injuries

    Inside the Garage

    Unsurprisingly, many household eye injuries occur inside the garage or workshop. In many cases, these accidents result due to a lack of protective eyewear. If you are using chemicals, working with tools, securing items with bungee cords, or doing a task that creates dust or other eye irritants, it’s important to use caution. Due to the dangers that these activities can pose, eye doctors advise that you and anyone nearby wear protective goggles to help avert accidents.

    In the Yard

    While people often worry about the safety of using a lawnmower due to the sharp blades, this type of equipment can present a different kind of hazard. While they may seem innocuous, the pieces of grass and the dust particles that become airborne as you mow can be a threat to your eyes, so use protective eyewear for this task. The same eye care advice goes for using power trimmers on your shrubs and hedges.

    Inside the House

    Many of the eye injuries that occur inside the home involve chemicals and hazardous items such as bleach and household cleaners, so always wear protective goggles when necessary, and wash your hands after using these products to avoid getting them into your eyes. If anyone in your household uses curling irons or other heated styling devices near their face, remind them to take care when using these appliances, so they can avoid inadvertently making contact with their eyes. Also, eye injuries can occur when cooking due to splashing oil or other hot liquids, so always take care while in the kitchen. Finally, eye doctors advise that you always use caution while drilling or hammering, and even while opening champagne bottles, to help avoid injuries.