There is some debate about whether myopia is a disease or a refractive error. The answer is uncovered by how myopia is defined and measured.

What Is The Definition Of A Disease?
The Review of Myopia Management provides a few definitions of disease to consider:

● A disease is any harmful deviation from the normal structural or functional state of an organism, generally associated with certain signs and symptoms and differing in nature from physical injury. (Encyclopedia Britannica, 2020)

● A disease is an abnormal condition affecting a living organism. Diseases are generally understood to be medical conditions that involve a pathological process associated with a specific set of symptoms. (Infectious Disease News, 2019)

Myopia, also called nearsightedness or shortsightness, is the inability to see objects at a distance and is the most common vision issue amongst children and adults. Myopia’s main symptom is blurry distance vision; however, the physiological implications of myopia is that the eyeball itself grows too long from front to back, see figure 1.

Myopia Is a Disease

Although myopia has symptoms like blurry vision, that aren’t caused by physical injury, myopia itself is caused by the eye growing too long. In other words, the axial length increases outside of the normal rate for a child’s age. See Figure 2

The elongation of the eye is the core issue. Dr. Thanh Mai, O.D. details, “The greater the myopia, the longer the axial length of the eye and thus greater risk. Myopia is clearly a disease. One that requires treatment to reduce the negative impact it can have on a person’s eye health and vision.”

Myopia is a significant, prevalent disease in children with increasing rates of progression. There are also two types of classifications: non-pathologic and pathologic myopia.