There is no single gene for eye color.  This was the conclusion that the researchers from the University of Queensland’s Institute for Molecular Bioscience (IMB) and the Queensland Institute of Medical Research had arrived to.  This study was first to prove such. The said researchers were able to discover that several genes influence the color of a person’s eyes.  However, some genes are more dominant in influencing eye color than others.

The leader of the research, Dr Rick Sturm of IMB, said that each individual has two types of the gene, having acquired one from each parent.  These versions can be the similar with each other or different.  Before, the determination of eye color was thought to be dependent on the simple Mendelian recessive trait.  For example, brown eyes were dominant than blue.  As such, a person would have brown eyes should the versions of his inherited genes were a pair of brown eye genes or one blue eye gene and one brown gene.  A person can have blue eyes only if his inherited genes were two blue.

However, the researchers believed that the single gene model of eye color inheritance was not enough to explain the variety of eye colors that humans have.  As such, they hypothesized that there are two major genes.  They believe that one major gene is responsible for controlling brown or blue outcomes and another is responsible for controlling green or hazel eye colors.  Other colors modify this trait. Furthmore, Dr. Sturm said that it is possible for two blue-eyed parents to have a brown-eyed child which is different to what was used to be thought. However, such is not a common case.

Dr Sturm further explains that the system of eye color determination is like a light bulb. The mechanism that decides whether an eye is brown or blue is similar to switching on a light.  On the other hand, an eye becoming green or hazel is similar to unscrewing a light bulb and putting in a different one. In relation to eye inspection, keratometers are instruments used for measuring the curvature of the front surface of the cornea, which is the covering of the eye.  The iris, which is the ring of muscle fibers located behind the cornea, contains the eye color.

Keratometers are also known as ophthalmometers.  These instruments are particularly used for assessing the degree and axis of astigmatism.  Keratometers were invented in 1880 by Samuel Hankins, a French ophthalmologist. Good keratometers should be able to allow quick and convenient measurements of the diameter of the cornea.  As such, the practitioner would be able to ascertain the volume of the eyeball. These diagnostic pieces of equipment are particularly effective in the prescription and fitting of spectacles.  This is because the measurements taken with the use of keratomers aids in harmonizing the lens vertex and the corneal vertex.  Moreover, keratometers are also helpful to contact lens practitioners. Furthermore, keratometers are employed in certain eye surgeries.  Such instruments are used in making precise incisions in cataract surgeries, as well as other corrective surgeries. Continue research on this page