You probably associate a trip to the optometrist with having your vision tested, and it's true that figuring out how good your eyesight is is the part of the examination that takes the most time. It's not the only thing that's happening during an appointment, though! They're also testing your overall eye health and making sure there are no nascent problems that might affect more than simply your glasses prescription--and here's how they're doing it.

Colour Vision Testing

Not everyone who has problems seeing different colours is aware of it, and sometimes colour blindness (particularly blue/yellow rather than the more standard red/green) can come on later in life when it's often a sign of a deeper issue that needs investigation. Optometrists will often administer simple colour blindness tests involving cards covered in coloured dots, even for people who are pretty confident their colour vision is normal.

Visual Field Testing

Everyone has a field of vision—the scope of what your eyes can see without moving. When people talk about peripheral vision or seeing something "out of the corner of their eye", their field of vision is what they mean! If this field starts to shrink or contains blind spots, it can cause pretty serious issues with your overall sight. It's also generally indicative of a deeper problem--so it's important to monitor it. This is usually done by asking you to look through a pair of goggles, hold a button device and watch a white screen for flashing lights. Every time you see a flash you press the button. Your success rate will tell your optometrist how good your visual field is.

Glaucoma Testing

The most reliable early test for glaucoma involves measuring the pressure inside your eyeball. There are several ways to do this, but the simplest and least invasive involves a device that administers a little puff of air right into your eye. This doesn't hurt, but it does feel weird to most people—and you may involuntarily blink on reflex in such a way that it has to be done more than once! Should this 'puff test' show any anomalies there are further tests that may require anesthetic eyedrops to perform so that the optometrist can take a closer look at your cornea.

Retinal & Slit Lamp Examinations

A 'slit lamp' is a device that allows an optometrist to see your eyeball more clearly, and requires you to look directly into a bright light for a short while. This is usually a visual examination that lets them check your blood vessels and pupil dilation. You may be given eyedrops containing a dye that helps show up potential problems, but this dye washes out of your eye naturally with a little blinking afterwards!

Contact an optometrist to schedule an eye examination today.