What is myopia?

Myopia (Nearsighted):

You see near better than far (even if neither are great)

Myopia is a very common type of eyeglass prescription that is seen with a minus sign (like -1.00 or -3.75). In fact, it is the most common type of eyeglasses prescription and it is becoming more common due to how much of our world is up close due to screens. As such, we recommend all children have an eye exam before the age of 1 and again before they enter kindergarten and every year thereafter. Vision problems do not hurt and children don’t understand how they are “supposed” to see, therefore a yearly comprehensive eye exam is essential!

The prescription strength of our glasses is determined by how long the eye is (axial length) and how steep the cornea is (corneal curvature). In nearsighted folks, the eye is slightly too long and/or the corneal curvature is too steep and this causes light to focus in front of the retina and create a blurry spot. Minus lenses help light focus on the retina. 

Myopia is caused by a mix of genetic and environmental factors and we still don’t fully understand the mechanisms of how it progresses. 

As far as genetics, a child is about 1.5 to 2 times more likely to develop myopia if 1 parent is nearsighted and up to 3 times more likely to develop myopia if both parents are nearsighted.

As far as environmental conditions, we know that exposure to sunlight is very important for the growth and development of vision. The recommendation is that children spend at least 2 hours outside each day. Additionally, the time spent doing near work, especially on screens, must be monitored. Frequent breaks are important. For every 25 minutes of up close work, take a 5 minute break to look far away. The general recommendation is 1 hour of “fun” screen time a day. “Fun” screen time means not educational related and includes anything on the tv, tablet, or phone. 

Common symptoms of nearsightedness include squinting when looking at something further away, eye strain, and headaches. 

Treatment options include glasses, contact lenses, or refractive surgery. 

The higher the minus power, the higher risk of developing retinal holes, tears, detachments and other retinal conditions. 

Thus, it is important to slow down the progression of myopia. Multifocal glasses (bifocals/progressives) and multifocal contact lenses can help slow down changes in prescription. Your doctor will discuss if this is a good option for you or your child.