Category: Cornea

What is astigmatism?

Astigmatism is a distorted shape of the lens or cornea that contributes to blurred vision.  It is not a disease, it does not cause blindness, and nearly everyone has at least some small amount of astigmatism. For example, take a look at the contact lenses below: The contact on the top is “round” and “spherical”.  This… Read More


Corneal Transplant Great for Keratoconus

You might want to know what an eye looks like before and after corneal transplantation for keratoconus. Keratoconus is a hereditary condition where the cornea gets thinner and steeper. This results in high astigmatism and blurred vision. If you have keratoconus, you have probably heard that you may need a corneal transplant at some time… Read More


What is the corneal epithelium?

Epithelium: the “skin of the cornea” The epithelium or “epi” of the cornea is a very thin and delicate layer of cells on the outer surface. It has many functions such as defining the shape of the tear film for good vision, protecting the cornea against infection, and refining the eye’s surface. The epithelium should… Read More


TearCare for dry eyes, styes, and meibomitis (MGD)

Nearly all of us suffer from dry eyes at some point and lid styes are not uncommon. Most dry eye symptoms and styes are caused by a problem with the oil glands of the eyelids. These are called meibomian glands. We call it meibomitis or meibomian gland dysfunction (MGD) when the meibomian glands are stopped… Read More


Why is my vision worse after cataract surgery?

Why would vision be worse after cataract surgery? When performing cataract surgery ophthalmologists are careful to maintain the health of the cornea.  Since I am a corneal specialist, I pay particular attention to protecting the cornea. Cataract surgery is one of the most successful surgeries performed in the United States.  Some patients who have had… Read More


What is corneal swelling (edema)?

Corneal swelling is also called corneal edema, bullous keratopathy, or corneal decompensation.  The cornea is the clear dome on the front of the eye.  It contains water like a damp sponge.  When the cornea has too much water, it swells.  The swelling makes it difficult for light to pass through the cornea.  This causes blurred… Read More


“Vital” Eye Research Review: Should scratch equal patch?

Does using an eye patch help when the corneal epithelium is scratched? Some ophthalmologists say yes and others say no. Cochrane is an international group of researchers that review peer-reviewed evidence to make health care decisions better. I value the reviews published by Cochrane because of their comprehensive review methodology and their unbiased reporting of… Read More


Reasons to Choose Dr. Vital to be your Houston Eye Doctor

If you live in Houston and are seeking a new eye doctor or surgeon, you may feel overwhelmed by the number of options out there. So, why choose Dr. Mark C. Vital to care for your vision? Here are quotes from several patients who chose Dr. Vital: “Our family is very grateful to Dr. Mark… Read More


“Vital” Eye Research Review: What is collagen crosslinking for keratoconus?

Collagen crosslinking is a procedure that has been performed in other areas of the world for many years but was approved by the FDA in the United States in 2016. The procedure aims to stiffen and strengthen the cornea by using riboflavin and ultraviolet light. This has been shown to be useful in the treatment… Read More


Dry Eye Causes and Solutions

Many think of dry eye as simply being caused by not having enough tears.  However, dry eye disease is generally much more complex than that.  It is important to remember that what you feel does not always match what we as eye doctors see on the eye’s surface.  For many patients, this can lead to confusion… Read More