Day: November 20, 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