An eye exam not only tests for visual impairment, but also for other underlying health issues. Even if you do not feel like you need glasses, many asymptomatic conditions exist that can be identified early on with an eye exam. A complete eye exam involves a series of tests designed to evaluate your vision and check for eye diseases. Each test during an eye exam evaluates a different aspect of your vision or eye health.
This is how the power of eyeglasses is calculated. This is what will tell the doctor if you area nearsighted, farsighted, have astigmatism, among other things.
"Which is better, 1 or 2?"
The "external" part of your eye includes your eyelids and eyelashes, cornea, iris, and lens of your eyes.
A slit lamp must be used to properly assess those structures. Only eye doctors offices have this instrument.
Patients with glaucoma, retinal tears or detachments, diabetic retinopathy, macular degeneration, freckles (nevi) and even tumors more often than not, have 20/20 vision and never have any pain.
The only way to find out is by having a retinal evaluation.
The normal retina is essentially transparent, although it does absorb a quantity of light passing through it.
A lot can happen in 12 months. The retina doesn't wait 2 years to start developing eye conditions...it can happen a month after your retinal evaluation. Early detection is key!
Most eye diseases are not related to age. Glaucoma and macular degeneration are 2 of the few which do mainly effect the older population. Other than that, every age is at risk for most eye diseases.
Many eye diseases have absolutely no correlation to overall health. Retinal holes, detachments, glaucoma, certain retinal hemorrhages and tumors to name a few.