Nearsighted? Farsighted?

Ever confused by what those medical terms means? Let’s break them down!

Emmetropia

This means that a person can see clearly at all distances and they do not need glasses. The eyeball is the correct length and the correct power so that images will land perfectly in focus on the retina (which is the “seeing” part of your eye).

Myopia (nearsightedness)

This means that a person can see objects that are near to them, but any objects far away are blurry. The eyeball is too long in length, and it has too much power in the system. This causes images to be formed in front of the retina and minus-powered lenses are required to fix it.

Hyperopia (farsightedness)

A person can see objects that are far away but cannot see objects that are near to them. The eyeball is too short and there is not enough power in the system. Images will be formed behind the retina and plus-powered lenses are needed to correct it.

…But wait! Hyperopia can be a little tricky. For folks under the age of 40 who have low amounts of hyperopia, they are sometimes able to “mask” the problem by using the eye’s natural focusing system called accommodation. By engaging this system, they can overcome small amounts of hyperopia and may be able to all distances just fine. However, this does require extra effort by the eyes and can sometimes lead to headaches, eyestrain, and visual fatigue.

Astigmatism

This will make all objects blurry whether they are near or far. Astigmatism occurs because the front of the eyeball is not perfectly round. (Think football shape rather than basketball shape.) This causes the retinal image to be distorted. Example: What happens when you look on the backside of a metal spoon? The reflection of your face is distorted in a “fun house mirror” effect. This is the same type of thing that happens to your vision with astigmatism. Just like myopia or hyperopia, astigmatism can be corrected with lenses.

 

Top image by Sankowski on Unsplash (location) used under Creative Commons Zero (CCO) License. Image has been cropped and modified from original. Image rights state commercial use and modifications allowed when image was obtained on 05/15/2017.

The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.