Month: November 2018

What Determines Your Eye Color

The Hargrave Eye Center’s latest post:

A person’s eye color has been the subject of many hit songs over the years. Have you ever asked yourself what actually makes up someone’s eye color? You may have learned about it in elementary school, but this article will give you a refresher course on what determines a person’s eye color.


The 46 chromosomes that make up your body have all of the information in them to determine what your eye color will be as well as vast amounts of other information for the rest of your body. One of the most important factors that determine your eye color are your genes. The genes are made up of alleles which have the information that creates your eye color. There are two types of alleles, dominant and recessive. The dominant allele will always be expressive if paired with a recessive allele. There are three alleles that can be present when determining eye color. Brown, Green, and Blue are the three alleles available from the gene pool. Brown and Green alleles are both dominant where Blue is recessive. A pair of alleles will equate to that eye color being represented. If a Brown or Green allele is paired with a Blue allele, the Brown or Green allele will be represented. Only when there are two Blue alleles present will the recessive gene be represented.


The other factor of eye color is how much melanin is present in the Iris of the eye. The Iris is the place in your eye that has color and is affected by the alleles. Melanin is the chemical that determines how light or how dark your eye color is. The more melanin that is present, the darker your eye color will be.

There are some variants in eye color with people of certain age groups and situational variations where people may have different eye colors temporarily. Children under the age of three usually have a blue color or tint to their eyes. Not until around the age of three is a person’s eye color solidified. In different situations, a person’s eye color may change. Variations in lighting may give people different eye colors for a short period of time. Over time melanin production in the eye could increase or decrease causing a person’s eye color to seem darker or lighter.

from Hargrave Eye Center

The Science Behind Sight

The Hargrave Eye Center’s latest post:

When you were younger, I’m sure you were explained how people see and interpret things. Typical examples of explaining sight include referring to cameras and how they operate. Demonstrating how your eyes see and how cameras work is an effective way to help people understand vision but our vision is much more complicated than that.


Our eyes are light receptors. Light is reflected off of an object which is then transferred into our eyes and processed by our brains. There are many different parts of the eye that allow the process of sight to happen. The components of a human eye are complex and deserve some explanation to understand how we see.


The areas of the eye that we use to perceive light consist of the pupil, cornea, retina, lens, and optic nerve. All of these areas work together at incredible speeds to process information from our eyes. In the retina of the eye, millions of light receptors differentiate colors and textures of objects we see. These receptors are divided into two categories, cones, and rods. The cone receptors in the retina are responsible for determining the color of the object we are perceiving. The rods in the retina give us the contrast between light and dark. The other components of the eye that were mentioned all help the receptors in the retina perceive and take in the light.

Cornea & Pupil

The cornea is the outermost layer of the eye. The best way to describe the cornea is to think of it as the window to the eye. The cornea allows light to safely pass through where the pupil filters how much of the light gets through. The pupil is the dark circle in the center of your eye. The pupil can frequently change in size depending on how much light is available to you. In the darkness, the pupil expands to allow as much light as possible into the eye. On a sunny day, the pupil shrinks to allow only a necessary amount of light through. The pupil can also alter its size based off of a person’s emotional state. Someone experiencing excitement can have a larger pupil size.

Lens & Optic Nerve

Your eye’s lens helps you to focus on objects both near and far. Very similar to a camera lens, your lens will adjust to the distance of the object you are trying to perceive. Through aging, the process of your lens adjusting becomes more difficult and may cause problems later on in life. Your optic nerve is the last component of your eye that is needed to perceive sight. The optic nerve runs from the back of your retina to the brain where the information received by your eye is interpreted and perceived.

from Hargrave Eye Center |Ocular Health Experts

Why You Shouldn’t Sleep In Your Contacts

The Hargrave Eye Center’s latest post:

If you wear contact lenses, then you may know the problems that arise from having them in too long or overnight. To most people, it is common knowledge that they should not wear their contacts overnight. Sleeping in your contacts can cause a wide array of problems starting with small, almost unnoticeable irritations to severe permanent damage. In this article, we will discuss a few issues that can arise from consistently sleeping in your contacts.


Your cornea is the outermost layer of your eye and is the portion of your eye that is most in contact with your contact lenses. Consistently sleeping in your contacts can lead to severe problems for your corneal health and overall sight. The cornea requires constant oxygen and the occasional flow of liquids from your glands to clean out debris and bacteria. Leaving contacts in overnight cuts off some oxygen flow to your corneas as well as tears created by your glands to filter out bacteria. Even within a short period, someone can experience dryness, irritation, or pain from dry and dirty contacts.


Prolonged use of contact lenses can lead to a variety of infections in the cornea. In severe cases, things like a corneal ulcer can form. The corneal ulcer forms from accumulated bacteria on the eye and can cause irritation, vision impairment, blindness, and strange sensations in the eye. Conjunctivitis or pink eye is a common infection that can be caused by dirty contact lenses. In rare cases, a person can experience Acanthamoeba keratitis which is an infection of the cornea from a single-celled organism, or ameba that invades the cornea. The Acanthamoeba can be found in water or soil and is most commonly transferred by improper care of contact lenses.


The best way to prevent eye injury and infection from contacts is to follow the instructed care of your lenses from a professional. Wash your hands before dealing with your contacts and remove your contacts before participating in an activity that involves being in the water. Schedule frequent checkups with your optometrist to evaluate your contact routine and receive examinations. Follow the instructions of your optometrist or contact lens packaging to ensure fresh and clean contacts throughout.

While you may not be intentionally sleeping in your contacts, always try to be aware when you have them in and to take them out at the necessary times to avoid any kind of impairment to your vision. Take care of your eyes!

from Hargrave Eye Center |Ocular Health Experts

Preparing Your Kids For Their Trip To The Eye Doctor

The Hargrave Eye Center’s latest post:

A trip to the doctor’s office can be intimidating for a young child. A trip to the Optometrist does not have to be a frightening experience. To ensure that you and your child have a good experience at the doctor’s office, consider following these steps to help your child prepare.


Before you schedule an appointment with the Optometrist, consider visiting the practice yourself to scope out the office. A kid-friendly doctor’s office will advertise as such. When visiting the office, speak with their staff to find out more information about the practice. Begin to create a relationship with the optometrist so you can understand how they work and what their values are. Having a friendly and welcoming environment for your child will help the trip go quickly.


A child’s fear of a doctor’s visit comes from them not knowing the reasoning behind going. Talk to your child about why they are going to the doctor’s and what to expect out of the visit. Highlight things like how the doctor will help them see better or what the benefits are of having healthy vision. Try to communicate to your child that the doctor’s office is nothing to be afraid of and perhaps even demonstrate some tests that will be taking place during the visit. Anything you can do to help your child feel at ease will help the entire process go smoothly.

Prepare questions for the doctor yourself. Inform them during the visit about any noticeable behaviors from your child that could influence their vision. Frequent headaches, squinting, or constant eye irritation are all things you should discuss with your doctor.


While waiting for your appointment at the doctor’s office, keep your child occupied. Bring games with you and play them while you wait. Keeping the child’s mind occupied on other things while in the waiting room will help keep the child calm.


After the appointment, make sure you follow through with any procedures the optometrist recommended. If your child needs eyeglasses, take them to pick out some frames for them. Give them a set of limited options so the choice is easier. Teach your child about basic eyewear cleanliness and care. Explain to them why they need the glasses and how it will help them day-to-day.

from Hargrave Eye Center

The Link Between Diabetes and Your Eyes

The Hargrave Eye Center’s latest post:

Diabetes can affect many different aspects of your life – even your eyes! Some common ailments can happen to your eyes due to diabetes. Without the steady of production of insulin that is characteristic of diabetes, there is not enough to break down the sugar in your blood. This results in hyperglycemia which is what can commonly affect many parts of your body as well as your eyes. Here are some common eye conditions that can come from diabetes.


One of the common eye conditions that can develop due to diabetes is cataracts. In fact, those who have diabetes are more likely to develop cataracts. Cataracts main symptom is cloudy vision, and this is due to the clear lens becoming obstructed and not allowing light to pass through it properly. This obstruction causes your eyesight to become blurry and even distorted. Cataracts are a result of additional glucose in the fluid in the front of the eye. The extra glucose causes the sorbitol levels to rise and leads to cloudy vision.


Those with diabetes are twice as likely to develop glaucoma. Neovascular glaucoma is one of the most likely conditions to emerge as a result of diabetes. Abnormal blood vessels in the retina characterize glaucoma, and they are a result of damaged central blood vessels. Common symptoms of glaucoma are vision loss or decreased vision, redness or pain.

Diabetic Macular Edema

Stemming from diabetic retinopathy, which is caused by damaged blood vessels in the retina, diabetic macular edema or DME is another common condition of the eyes resulting from diabetes. DME is also caused by damaged blood vessels but also by an accumulation of fluid in the macula. Almost 30% of those with diabetes will develop diabetic macular edema.

Eye conditions are likely to develop for those with diabetes, but there are steps that you can take to combat them. Proactively having yearly eye exams and dilated eye exams is very important to stay on top of possible symptoms. Following a proper diet and keeping your blood sugar and glucose levels under control and at the appropriate levels is crucial. A final step is ensuring that you maintain a healthy lifestyle and your doctor’s recommended diet. Be sure to watch out for any symptoms and talk to your doctor immediately if anything unusual develops.

from Hargrave Eye Center

Tech That is Helping Restore Sight

The Hargrave Eye Center’s latest post:

Many technologies are exploring the possibility of reversing blindness or slowing down vision loss. These technologies take a variety of different forms; the ongoing research consists of cell-based solutions, devices, surgical solutions, and tech-based nonsurgical solutions. There is also an emerging number of artificial intelligence and other technologies that are being used and refined to help those with vision impairment.

Cell-Based Solutions

One of the most breakthrough cell-based technologies is the concept of gene therapy as a method of correcting vision loss for those who have childhood-onset blindness.  Gene therapy is the process of replacing any missing or defective genes within cells with healthy, functioning ones. Retinal cell implants are another cell-based technology that specifically targets those with age-related macular degeneration. These cells come from human embryonic stem cells. These cell-based solutions are still in the early stages of implementation but are very promising for the future of sight restoration.

Device-Based Solutions

There are quite a few device-based technologies that are working, not only to provide solutions to reverse vision loss but to help those navigate life with impaired vision. Some of these solutions to reverse blindness or vision loss consist of 3D printed eyes, corneal inlays, and possibly bionic eye-brain implants. There are also apps that provide aid to those with blindness, such as Be My Eyes and Seeing AI. IrisVision has even integrated vision assistance with virtual reality, to help with everyday tasks.

Surgical Solutions

Surgical solutions to vision impairment are some of the more common technologies that are available. The most common is Lasik surgery, in which a surgeon reshapes a patient’s cornea with a tiny laser. Other types of surgery are RLE or a clear lens extraction and RK where the cornea is flattened.

Tech-Based Nonsurgical Solutions

One of the most interesting nonsurgical solutions is a Gentle Vision retainer shaping systems. These are lenses that someone would wear while sleeping, similar in style to contact lenses, that slowly and gently reshape the cornea. Eye drops are also being developed to help reverse cataracts.

Technology can take many different forms, and there are developments in all of the facets of it in the quest for vision repair. There is still far to go in this area of development, but exciting things are on the horizon for our eyes!

from Hargrave Eye Center

Supplements for Eye Health

The Hargrave Eye Center’s latest post:

There are many different vitamins and minerals that your eyes need, and that can truly benefit them. Proactively ensuring that you are getting all the vitamins that your eyes need is a way to lower your risk of Age-Related Macular Degeneration, or AMD, and severe vision loss due to other age-related eye diseases. A proper diet should be the primary source of your necessary vitamins and minerals, but supplements can be a great way to get additional vitamins into your system.

Lutein and Zeaxanthin

Taking lutein and zeaxanthin supplements helps increase the density of carotenoids in your retina. They can also help to absorb ultra-violet lights that try to damage your eyes. It is possible that a proper amount of these vitamins could help to prevent cataracts and other AMDs. Lutein and Zeaxanthin can be found in foods such as cooked kale and spinach, and even in eggs. If making sure your diet contains enough of these minerals is not possible, taking small doses in supplements can be an option.


Zinc, like lutein and zeaxanthin, is found in your eyes naturally but it is a powerful vitamin that protects your eyes against cell damage. Foods such as poultry, seafood, and red meat as well as nuts and beans contain zinc and are essential aspects of a diet to ensure proper amounts of zinc. Increasing your zinc intake can be important for those who have a high risk of developing AMD. Taking a zinc supplement can be the best way to get the additional amounts of the vitamin, and it is recommended that copper is taken in tandem with zinc, as high levels of zinc can heighten copper absorption.

Vitamin B1

Vitamin B1 is essential to the health of your eyes. Proper amounts of this vitamin can be helpful in preventing cataracts, glaucoma and other vision diseases. Vitamin B1 is commonly found in yeast, cauliflower, eggs, and pork. Generally, the Western diet accounts for about half of the recommended amount of the vitamin. It can be helpful to take a supplement for it if you are unable to get the correct amount from your diet.

Supplements are not the end-all for any ailment that comes along, including those of your eyes, but they can be beneficial in supporting your daily diet. Lutein and zeaxanthin can help the absorption of UV rays, zinc can protect against cell damage in your eyes, and vitamin B1 is essential to the overall health of your eyes.

from Hargrave Eye Center