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Eye Exam

What Exactly is an Eye Chart?

If there’s one aspect of optometry that everyone recognizes, it’s the traditional eye chart, with its rows of big letters on top, which gradually become smaller the farther down you go. This chart is usually known as the Snellen chart.

Yet how much do you really know about this eye chart? Are all eye charts the same? How are these eye charts used? And when were they invented?

Here’s everything you need to know about eye charts and more!

What is an Eye Chart?

An eye chart is one of the tools your eye doctor uses to assess your eyesight. Based on how well you can see various letters on the chart, your optometrist will determine whether you have myopia (nearsightedness), hyperopia (farsightedness), presbyopia (age-related farsightedness) or astigmatism, and will measure the prescription that will give you the clearest, most comfortable vision.

Are All Eye Charts The Same?

There are a number of variations to the standard Snellen eye chart. The one an eye doctor uses depends on the personal needs and abilities of the patient. For example, eye doctors will use charts with pictures or patterns for younger children who may not have learned to read or identify letters and numbers.

There are also certain charts that specifically measure distance vision, while others are better for measuring near vision.

History of the Snellen Eye Chart

The Snellen eye chart was developed by Dutch eye doctor Hermann Snellen in the 1860s. Before this standardized eye chart was developed, each eye doctor had their own chart that they preferred to use.

Having so many different eye charts made it impossible to standardize the vision correction available to patients. Eyeglass makers didn’t receive the defined measurements they needed to accurately design, manufacture and measure the optical prescriptions their patients needed.

For the first time, the Snellen eye chart allowed a person to provide a standardized prescription from any eye care provider they chose to any eyeglass maker, and get the same optical lenses to accurately correct their vision.

How The Snellen Chart Is Used in Eye Exams

The standard Snellen chart displays 11 rows of capital letters, with the first row consisting of a single large letter. The farther down the chart you go, the smaller the letters become.

Your eye doctor will ask you to look through a phoropter – an instrument used to test individual lenses on each eye during an eye exam – and look at the Snellen chart placed 20 feet away. Your eye doctor will prescribe the lenses that provide you with the clearest and most comfortable vision.

In many offices, where 20 feet of space may not be available, you’ll be asked to view the chart through a mirror. This provides the same visual experience as if you were standing 20 feet away.

If you have 20/20 vision, it means you can see what an average person can see on an eye chart from a distance of 20 feet. On the other hand, if you have 20/40 vision, it means you can only see clearly from 20 feet away what a person with perfect vision can see clearly from 40 feet away.

If you have 20/200 vision, the legal definition of blindness, this means what a person with perfect vision can see from 200 feet away, you can see from 20 feet away.

Does 20/20 Visual Acuity Mean Perfect Vision?

No. While eye chart tests identify refractive errors, they can’t detect signs of visual skill deficiencies or diseases such as glaucoma, cataracts or macular degeneration. These are diagnosed using advanced equipment as part of a comprehensive eye exam with your local eye doctor. Early diagnosis and treatment of eye conditions are essential to ensuring long-term vision and eye health.

For more information, give us a call at or visit us in person at , today!

Q&A With Your Local Optometrist

How do you keep your eyes healthy?

You only have one set of eyes – don’t take them for granted!

Make sure to implement the following habits for healthy eyes (and body). These include:

  • Eating a balanced diet rich in fiber, fruits and vegetables
  • Drinking plenty of water to hydrate your body and eyes
  • Not smoking, and avoiding 2nd-hand smoke
  • Wearing sunglasses to protect your eyes from ultraviolet (UV) rays
  • Maintaining normal BMI with regular exercise
  • Regular visits to your eye doctor as recommended

What health conditions can an eye exam detect?

A comprehensive eye exam can often detect certain underlying diseases that can threaten your sight and eye health, such as diabetes, high blood pressure, high cholesterol, tumors, autoimmune conditions and thyroid disorders. This is why having your eyes checked regularly is key. The earlier the diagnosis and treatment, the better the outcome and the higher your quality of life.

9 Signs Your Child Might Need Glasses

It can sometimes be hard to tell if your child is having trouble seeing. That’s because children are often unaware of their own vision problems, and in many cases may not even have the words to describe what they’re seeing.

Though eye and vision problems are very common in school-age children, the signs are often subtle and easy to miss. When these issues go undiagnosed and untreated, a child may have difficulty learning in the classroom and playing sports, among other things. Fortunately, some vision issues can be easily solved with a simple pair of eyeglasses.

Here are 9 subtle signs that your child may need glasses:

1. They struggle with intense near vision activities like homework, computer use, taking exams or reading. They may also avoid distance vision activities such as sports.

2. They have a hard time keeping their place while reading

3. They tilt their head or squint when watching TV or in class

4. They have problems with unusually teary eyes or frequently rub or squint their eyes

5. They complain about eye fatigue and headaches, especially after reading or other vision-intensive activities

6. They may close one eye while reading or watching TV in order to see better

7. They hold books unusually close to their face in order to read

8. They sit very close to TVs or computer screens in order to see better

9. They use their finger to guide their eyes along the page as they read.

If you notice these or any other signs that your child may be experiencing poor vision, it is important to bring them in for a pediatric eye exam as soon as possible.

Pediatric Eye Exams and Eyeglasses

During your child’s eye exam our eye doctor will test for signs of refractive errors such as myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. If your child has a refractive error, our eye doctor will prescribe prescription glasses to correct their vision and help them thrive at school and at home.

School aged students may be prescribed eyeglasses if their eyes have difficulty focusing. The glasses allow the eyes to function better and remove eye strain. These eyeglasses are often only worn when in class, when reading, using a digital screen or during examinations.

Once the optometrist determines your child’s prescription, our friendly and professional optical team can help you and your child choose just the right frames. Our wide selection of designer frames includes designs and materials to fit every need and sense of style. From versatile metal or polycarbonate frames that can stand up to the rigors of sports, to lightweight frames that are comfortable to wear during the school day, has you covered.

For more information on how to tell if your child needs glasses, and how our eye care practice can help, call us at or visit us in person today!

At Premier Eye Associates, we put your family’s needs first. Talk to us about how we can help you maintain healthy vision. Call us today: 856-858-3937 or book an appointment online to see one of our Collingswood eye doctors.

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Q&A

Can refractive errors cause problems other than poor vision?

Yes. Myopia in childhood has been linked to an increased risk of developing potentially sight-threatening eye conditions later in life. These conditions include glaucoma, macular degeneration and cataracts. Speak to your eye doctor about the best ways to minimize your child’s risk.

Will wearing glasses weaken my child’s vision?

No. Many people mistakenly believe that eyeglasses make your eyes reliant on them, and that this reliance weakens your eyes. Children with refractive errors will experience changes in their vision, even when their nearsightedness, farsightedness or astigmatism isn’t corrected with glasses or contact lenses.

10 Ways to Give Your Eyes Some Love This Valentine’s Day

Valentine’s Day is the time to express your love and appreciation to those you care about most. But it’s also a great opportunity to take the time to pamper yourself — so why not start with your eyes? 

Practice these 10 healthy lifestyle habits to help protect your eye health and vision.

1. Be Mindful of the Food You Eat

Fill your plate with fresh fruits and veggies, lean proteins and whole grains. A well-balanced diet is good for your body and can lower your risk of eye disease.

Studies show that foods high in vitamins A, C, E, Omega-3, lutein and zeaxanthin are especially beneficial for promoting eye health.

2. Drink Plenty of Water 

Drinking at least eight 8-ounce glasses of water each day will keep your body hydrated and your eyes moist — which is essential for preventing dry eye syndrome. To add some flavor to your water, try adding a splash of lemon juice or swap some of those glasses of water for an herbal tea or other non-caffeinated beverage. Caffeinated drinks have a dehydrating effect, so try to limit your coffee consumption as much as possible.

3. Exercise Regularly

Exercise is widely known for its physical and mental health benefits, but studies show that it can also lower your risk of serious eye conditions and diseases. Cardio exercise in particular has been shown to lower eye pressure and improve blood flow to the retina and optic nerve at the back of the eye. So grab your gym bag and get moving!

4. Don’t Smoke 

If you’ve been thinking about quitting, there’s no better time than now. Smoking tobacco significantly raises your risk of developing sight-threatening eye diseases like diabetic retinopathy, cataracts and age-related macular degeneration (AMD), and can also lead to their early development.

Smoking also robs the body of the essential vitamins and minerals it needs to maintain eye health, and contains around 7,000 chemicals that can lead to eye irritation and dry eye.

5. Practice Good Makeup Hygiene

While wearing makeup can accentuate your eyes and make you feel more beautiful, it’s important to note that if not used properly, certain makeup products can adversely affect eye health. 

To keep your eyes and vision healthy, make sure to:

  • Clean your brushes and applicators regularly
  • Toss any expired products, or eye makeup you’ve used during an eye infection
  • Only apply makeup to the outer margin of your eyelids
  • Remove your makeup before going to bed
  • Never share makeup or use in-store testers

Following these safety tips will help to lower your risk of eye infections and other serious complications. 

6. Wear Sunglasses

Studies show that prolonged UV exposure can damage the eyes and lead to the development of sight-threatening eye conditions, like cataracts, macular degeneration and glaucoma, in the future. 

Purchase a pair of stylish sunglasses with 100% UV protection and wear them any time you venture outdoors — the sun’s UV rays can penetrate the clouds and reflect off of snow, sand, water and pavement. So keep a pair of sunglasses next to your front door and a spare pair in your bag or car to ensure you have UV protection wherever you go. 

7. Prevent Eye Injuries

About 90% of vision loss from eye injuries can be prevented by wearing the right eye protection.  

Protective eyewear like sports goggles or glasses with polycarbonate lenses are designed with sturdy materials that are less likely to break or shatter while you play sports, and can protect your eyes from small particles that fly in the air when you mow the lawn or engage in DIY projects. 

8. Learn First Aid for Eye Injuries

Let’s be real, accidents can happen even if we take all the right measures to protect ourselves. But knowing what to do in case of an unexpected eye injury can potentially save you or someone you love from permanent eye damage or vision loss. 

Note: Any type of eye injury should be taken seriously, and promptly examined by an eye doctor. 

9. Avoid Digital Eye Strain

Prolonged screen time can cause eye strain, dry eyes, blurry vision and headaches — and lead to a condition called digital eye strain, also known as computer vision syndrome.

Avoid symptoms of digital eye strain by limiting screen time as much as possible. If prolonged screen time is unavoidable, practice the 20-20-20 rule: set an alarm on your phone as a reminder to take breaks every 20 minutes to focus on an image at least 20 feet away, for at least 20 seconds.

10. Visit Your Eye Doctor 

Regular eye exams are crucial when it comes to maintaining your eye health. With an eye exam, your eye doctor can identify early signs of sight-threatening eye diseases and conditions — enabling earlier treatment and increasing your chances for optimal results. 

From all of us at Premier Eye Associates in Collingswood, we wish you a Happy Valentine’s Day! 

 

Q&A

What’s the difference between an eye exam and vision screening?

Vision screenings are basic tests of visual acuity, generally conducted by a school nurse or pediatrician. These screenings can’t identify many vision conditions that impact learning or work performance, and are unable to detect ocular health problems.

A comprehensive eye exam, which is performed by an eye doctor, includes tests for visual acuity and functional vision, as well as close examination of the inner and outer structures of the eye. 

How often do I need to have an eye exam?

According to the American Optometric Association (AOA), it is important to have your eyes examined every one to two years, depending on your age, whether or not you wear glasses or contacts, your family history of eye disease, and your ocular health to date. Annual eye exams help your eye doctor monitor your eye health and easily identify any changes in your vision. 

The Importance of Eye Exams for Contact Lenses

Are you planning on wearing contact lenses for the first time? Do you need a new contact lens prescription? Are your current contacts not as comfortable as you wish they were? Your eye doctor will perform a contact lens eye exam to ensure that your vision with contacts is clear, comfortable, and safe, providing you with the right lenses for you. 

What is a contact lens exam?

If you wear or want to wear contact lenses, you’ll need an eye exam for contact lenses, in addition to your regular comprehensive eye exam. Special tests are performed during a contact lens exam to evaluate your eyes and vision with contacts. 

Are eyeglass prescriptions the same as contact lens prescriptions?

No, a prescription for glasses cannot be used for contact lenses. An eyeglass prescription is for lenses that are positioned approximately 12 millimeters from your eyes, whereas a contact lens prescription is measured for lenses that sit directly on the surface of your eye.

The prescription for contact lenses also includes the brand, lens diameter and curvature, which are not part of an eyeglass prescription.

Contact lenses fitting: One size does not fit all

One contact lens size doesn’t fit all eyes. If a contact lens is too flat or too steep for your corneal shape, you may experience discomfort or even eye damage. Your eye doctor will take certain measurements to determine the best contact lens design and fit for your eyes. 

Corneal curvature

This measures the curvature of your eye’s clear front surface (cornea) so the eye doctor can select the optimal curve and diameter for your contact lenses. If your eye’s surface is somewhat irregular because of astigmatism or other conditions, you may require a special lens. 

Pupil and iris size

The size of your pupil and iris (the colored part of your eye) is also important in determining the best contact lens design.

Tear film evaluation

This test evaluates the quality of your tears, to determine whether they will be able to keep contact lenses and your cornea sufficiently hydrated throughout the day. If you have dry eye disease, standard contact lenses may not be right for you. 

Trial lenses

Following the eye exam, you will be provided with trial lenses to verify that the chosen contact lenses offer clear and comfortable vision. This will allow the eye doctor to make any fine adjustments to the prescription.

Contact Lens Eye Exam Near You

Wearing the correct contact lenses for your eyes allows you to enjoy all of the benefits of wearing contacts, while keeping your eyes healthy and comfortable. 

If you’re already a contact lens wearer, visit your eye doctor at least once a year to make sure the lenses are still providing you with optimum vision and comfort.

Contact Premier Eye Associates in Collingswood to book your contact lens eye exam today!