Like ultraviolet radiation, visible blue light — the portion of the visible light spectrum with the shortest wavelengths and highest energy — has both benefits and dangers. Here are important things you should know about blue light:

1. Blue light is everywhere.
Sunlight is the main source of blue light and being outdoors during daylight is where most of us get most of our exposure to it. But there are also many man-made, indoor sources of blue light, including fluorescent and LED lighting and flat-screen televisions.

Most notably, the display screens of computers, electronic notebooks, smartphones and other digital devices emit significant amounts of blue light. The amount of HEV (High Energy Visible Light) light these devices emit is only a fraction of that emitted by the sun. But the amount of time people spends using these devices and the proximity of these screens to the user’s face have many eye doctors (Harvard Health Letter) and other health care professionals concerned about possible long-term effects of blue light on eye health.

2. HEV light rays make the sky look blue.
The short-wavelength, high-energy light rays on the blue end of the visible light spectrum scatter more easily than other visible light rays when they strike air and water molecules in the atmosphere. The higher degree of scattering of these rays is what makes a cloudless sky look blue.

3. The eye is not very good at blocking blue light.
Anterior structures of the adult human eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. In fact, less than one percent of UV radiation from the sun reaches the retina, even if you aren’t wearing sunglasses.
(Keep in mind, though, that sunglasses that block 100 percent of UV are essential to protect these and other parts of the eye from damage that could lead to cataracts, snow blindness, a pinguecula and/or pterygium, and even cancer.)

On the other hand, virtually all visible blue light passes through the cornea and lens and reaches the retina.

4. Blue light exposure may increase the risk of macular degeneration.
The fact that blue light penetrates all the way to the retina (the inner lining of the back of the eye) is important, because laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells in the retina. This causes changes that resemble those of macular degeneration, which can lead to permanent vision loss.

Although more research is needed to determine how much natural and man-made blue light is “too much blue light” for the retina, many eye care providers are concerned that the added blue light exposure from computer screens, smartphones and other digital devices might increase a person’s risk of macular degeneration later in life.

5. Blue light contributes to digital eye strain.
Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you’re looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to digital eye strain.

Research has shown that lenses that block blue light with wavelengths less than 450 nm (blue-violet light) increase contrast significantly. Therefore, computer glasses with yellow-tinted lenses may increase comfort when you’re viewing digital devices for extended periods of time.

6. Blue light protection may be even more important after cataract surgery.
The lens in the adult human eye blocks nearly 100 percent of the sun’s UV rays. As part of the normal aging process, the eye’s natural lens eventually blocks some short-wavelength blue light as well — the type of blue light most likely to cause damage to the retina and lead to macular degeneration and vision loss.

If you have cataracts and are about to have cataract surgery, ask your surgeon what type of intraocular lens (IOL) will be used to replace your cloudy natural lens, and how much blue light protection the IOL provides. After cataract surgery you might benefit from eyeglasses that have lenses with a special blue light filter — especially if you spend long hours in front of a computer screen or using other digital devices.

7. Not all blue light is bad.
So, is all blue light bad for you? Why not block all blue light, all the time?

Bad idea. It’s well documented that some blue light exposure is essential for good health. Research has shown that high-energy visible light boosts alertness, helps memory and cognitive function and elevates mood.

In fact, something called light therapy is used to treat seasonal affective disorder (SAD) — a type of depression that’s related to changes in seasons, with symptoms usually beginning in the fall and continuing through winter. The light sources for this therapy emit bright white light that contains a significant amount of HEV blue light rays.

Also, blue light is very important in regulating circadian rhythm — the body’s natural wakefulness and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm. But too much blue light late at night (reading a novel on a tablet computer or e-reader at bedtime, for example) can disrupt this cycle, potentially causing sleepless nights and daytime fatigue.

Every experience a preschooler has is an opportunity for growth and development. They use their vision to guide other learning experiences. From ages 2 to 5, a child will be fine-tuning the visual abilities gained during infancy and developing new ones.

Stacking building blocks, rolling a ball back and forth, coloring, drawing, cutting, or assembling lock-together toys all help improve important visual skills. Preschoolers depend on their vision to learn tasks that will prepare them for school. They are developing the visually-guided eye-hand-body coordination, fine motor skills and visual perceptual abilities necessary to learn to read and write.

Steps taken at this age to help ensure vision is developing normally can provide a child with a good “head start” for school.

Preschoolers are eager to draw and look at pictures. Also, reading to young children is important to help them develop strong visualization skills as they “picture” the story in their minds.

This is also the time when parents need to be alert for the presence of vision problems like crossed eyes or lazy eye. These conditions often develop at this age. Crossed eyes or strabismus involves one or both eyes turning inward or outward. Amblyopia, commonly known as lazy eye, is a lack of clear vision in one eye, which can’t be fully corrected with eyeglasses. Lazy eye often develops as a result of crossed eyes but may occur without noticeable signs.

In addition, parents should watch their child for indication of any delays in development, which may signal the presence of a vision problem. Difficulty with recognition of colors, shapes, letters and numbers can occur if there is a vision problem.

The preschool years are a time for developing the visual abilities that a child will need in school and throughout his or her life. Steps taken during these years to help ensure vision is developing normally can provide a child with a good “head start” for school.

Signs of Eye and Vision Problems
According to the American Public Health Association, about 10% of preschoolers have eye or vision problems. However, children this age generally will not voice complaints about their eyes.
Parents should watch for signs that may indicate a vision problem, including:

  • Sitting close to the TV or holding a book too close
  • Squinting
  • Tilting their head
  • Frequently rubbing their eyes
  • Short attention span for the child’s age
  • Turning of an eye in or out
  • Sensitivity to light
  • Difficulty with eye-hand-body coordination when playing ball or bike riding
  • Avoiding coloring activities, puzzles and other detailed activities

If you notice any of these signs in your preschooler, arrange for a visit to your Doctor of Optometry.

Understanding the Difference Between a Vision Screening and a Vision Examination
It is important to know that a vision screening by a child’s pediatrician or at his or her preschool is not the same as a comprehensive eye and vision examination by an optometrist. Vision screenings are a limited process and can’t be used to diagnose an eye or vision problem, but rather may indicate a potential need for further evaluation. They may miss as many as 60% of children with vision problems. Even if a vision screening does not identify a possible vision problem, a child may still have one.

Passing a vision screening can give parents a false sense of security. Many preschool vision screenings only assess one or two areas of vision. They may not evaluate how well the child can focus his or her eyes or how well the eyes work together. Generally, color vision, which is important to the use of color coded learning materials, is not tested.

Between the ages of 3 and 5, your child should have a thorough, in-person optometric eye examination to make sure his or her vision is developing properly and there is no evidence of eye disease. If needed, your Doctor of Optometry can prescribe treatment, including eyeglasses and/or vision therapy, to correct a vision development problem.

With today’s diagnostic equipment and tests, a child does not have to know the alphabet or how to read to have his or her eyes examined. Here are several tips to make your child’s optometric examination a positive experience:

  • Make an appointment early in the day. Allow about one hour.
  • Talk about the examination in advance and encourage your child’s questions.
  • Explain the examination in terms your child can understand, comparing the E chart to a puzzle and the instruments to tiny flashlights and a kaleidoscope.

Unless your Doctor of Optometry advises otherwise, your child’s next eye examination should be when he or she starts school, around 6 years of age. By comparing test results of the two examinations, your optometrist can tell how well your child’s vision is developing for the next major step into the school years.

What Parents Can Do to Help with Preschool Vision Development
Playing with other children can help developing visual skills.

There are everyday things that parents can do at home to help their preschooler’s vision develop as it should. There are a lot of ways to use playtime activities to help improve different visual skills.

Toys, games and playtime activities help by stimulating the process of vision development. Sometimes, despite all your efforts, your child may still miss a step-in vision development. This is why vision examinations at ages 3 and 5 are important to detect and treat these problems before a child begins school.

Here are several things that can be done at home to help your preschooler continue to successfully develop his or her visual skills:

  • Practice throwing and catching a ball or bean bag
  • Read aloud to your child and let him or her see what is being read
  • Provide a chalkboard or finger paints
  • Encourage play activities requiring hand-eye coordination such as block building and assembling puzzles
  • Play simple memory games
  • Provide opportunities to color, cut and paste
  • Make time for outdoor play including ball games, bike/tricycle riding, swinging and rolling activities
  • Encourage interaction with other children.

There are numerous foods that are rich in essential vitamins, nutrients, and antioxidants that are highly beneficial for eye health. From leafy greens to nuts and seeds and everything in between, discover the best top ten foods that will not only improve an individual’s eyesight but support healthy vision too.

Spinach and kale contain high amounts of lutein, which has been found to reduce the risk of age-related eye diseases. Spinach and kale also contain antioxidants that shield eyes from sunlight damage and exposure to air pollutants. Other plant foods that contain lutein are collard greens, turnip greens, romaine lettuce, and broccoli. Aside from supporting healthy vision, leafy greens are low-fat, fibrous foods that improve heart health. Smoothies containing leafy greens have become increasingly popular due to more individuals relying on greens for energy.

Orange and yellow vegetables contain beta-carotene. Beta-carotene acts as an aid in proper immune system function and to support healthy skin. Once it is absorbed into the body, it helps produce vitamin A, which is incredibly good for a person’s eyesight for several reasons. Vitamin A is known to help to reduce inflammation in the body, support neurological function, and help protect against infections within the body. Alternative food sources of beta-carotene are sweet potatoes, cantaloupe, apricots, squash, and pumpkin. Consuming enough vitamin, A from food sources is a preventative measure against having to ingest oral supplements.
Seeds and nuts are a balanced source of vitamin E and are beneficial to human body tissue. A small serving of almonds, sunflower seeds or pecans provides the daily requirement of vitamin E. Known for its ability to support healthy skin and eyes in humans; Vitamin E can also partially shield eyes from the sun’s harmful ultraviolet rays. Vitamin E preserves the cells in the eyes and protects against vision problems like macular degeneration. Some alternatively take vitamin E as a beauty supplement, as it is known to support healthy hair and skin. Vitamin E can also be used as in oil form to fight wrinkles and other signs of aging.
Omega-3 is a type of fatty acid essential to body function and is known as a good fat. Omega-3 provides numerous health benefits. For instance, studies conducted in infants found that getting the necessary amount of omega-3 was essential in optimal vision development. Omega-3 is also believed to help prevent dryness in the eyes. Fish are among the food’s rich in omega-3; tuna, salmon, herring, mackerel, trout, and sardines are among the best kinds for optimal Omega-3 consumption. Omega-3 is also found in flaxseed, canola oil, and roasted soybeans. It is recommended to get the required amounts of omega-3 from food rather than oral supplements.
Zinc helps to support a healthy brain and immune system. Many are unaware of the fact that a zinc deficiency can make one more susceptible to infection. Zinc also acts as an aid to Vitamin A in creating melanin, a pigment that protects the eyes. If one is deficient in zinc, night vision is also known to be affected. Although supplements have been reported not to show any improvement in night vision, some research does show that zinc supplements can slow the progression of macular degeneration – a vision problem which worsens with age. Zinc-rich foods to improve and support health eyesight are pumpkin seeds, whole wheat, lean beef, fortified cereals, lean pork, and lamb.

Vitamin C, also called ascorbic acid, acts as an antioxidant. Vitamin C helps develop and maintain body tissue as well as collagen located in the corneas. Some scientific research even shows that vitamin C may reduce the risk of cataracts. Vitamin C is also used to make skin cells, blood vessels, ligaments, and tendons. Many fruits and vegetables are rich in vitamin C, including all the following: oranges, grapefruit, limes, and tomatoes. It is best to speak with a healthcare provider concerning necessary daily amounts of vitamin C.

As previously mentioned, vitamin C can be a great aid in supporting eye health. Red bell peppers not only contain vitamin C but vitamins A and E as well. Adding red peppers into your diet would be an added way of receiving an extra strength dosage of vital nutrients. It is recommended to eat the peppers raw, as heat can break down vitamin C. A salad with uncooked peppers is an easy way of maintaining good vision. Red peppers are also known to be especially beneficial to blood vessels located in the eyes.

Most individuals know that carrots support eye health, but few are aware that eggs can be a necessary component in promoting good vision. For instance, zinc found in eggs help the body process and use lutein. Nutrients found in eggs increase the amount of the eye’s protective pigment. Egg yolk aids in blocking harmful light from entering the retina of the eye. Eggs can provide other essential nutrients as well because egg whites contain more than half the egg’s protein and are also a good source of vitamins D, B12, and B6. Egg whites also include selenium, copper, and iron.

For those who love meat, consuming a few servings of lean meat or poultry can be very beneficial. Not only do these foods leave an individual feeling full and satisfied, but they also contain zinc which helps to make melanin, the protective pigment in eyes. Good sources of zinc are lean beef, chicken (either white or dark meat) and pork. Oysters are known to have the highest levels of zinc per serving than any other seafood. Other seafood containing zinc are lobsters, shrimp, and crabs. Some of these foods are delicacies and can be expensive, however, it is important to note that individuals need a relatively small amount of zinc in their diet.

Bean-lovers will be glad to learn that both beans and legumes may help to slow macular degeneration. Legumes and beans can also support healthy night vision. An added benefit to eating beans is that they are known to be heart-healthy, low-fat foods. Chickpeas, black-eyed peas, lentils and kidney beans are all good sources of fiber as well. Eating legumes and beans can also give you the daily recommended amounts of protein, antioxidants, and potassium, too. Beans and legumes are versatile foods and can be eaten alone, or added to stews, chili or soups. Dry beans can be easily stored and are inexpensive as well.