Eye exams check more than vision clarity
It is easy to assume that if you see clearly, your eyes are fine. In practice, vision clarity is only one part of what a comprehensive eye exam assesses.
A thorough eye exam evaluates:
- Vision acuity and prescription — how clearly you see at various distances
- Eye pressure — elevated pressure is a key risk factor for glaucoma
- Optic nerve health — assessed for signs of glaucoma or other damage
- Retina and macula — checked for diabetic changes, macular degeneration, and other conditions
- Anterior structures — cornea, lens, and anterior chamber for disease or early cataract
- Binocular function — how your eyes work together
Many of the most important findings have nothing to do with whether your glasses prescription needs updating.
Conditions that develop without symptoms
Several common and serious conditions are asymptomatic in early stages:
Glaucoma damages peripheral vision gradually. Because the brain compensates for early peripheral loss, most patients do not notice changes until the disease is advanced. Eye pressure measurement and optic nerve imaging allow early detection long before vision loss becomes apparent.
Diabetic retinopathy affects the small blood vessels of the retina. In early stages it causes no visual symptoms. Without regular monitoring, it can progress to severe vision loss or blindness — yet it is highly manageable when identified early.
Age-related macular degeneration (AMD) in its early and intermediate stages is often asymptomatic. Detecting it early allows monitoring and, in the wet form, treatment before central vision is affected.
Elevated eye pressure carries risk even in the absence of diagnosed glaucoma, and is only detectable through measurement.
What eye exams can reveal about overall health
The retina is the only tissue in the body where blood vessels and nerves can be directly observed without a surgical procedure. Changes in the retinal vessels can reflect systemic disease:
- Diabetic changes may be visible before a person has received a diabetes diagnosis
- Hypertensive retinopathy can indicate uncontrolled blood pressure
- Signs of high cholesterol and cardiovascular disease are sometimes seen in retinal vessels
An eye exam occasionally becomes the first place a systemic condition is identified.
How often to go
Most adults benefit from a comprehensive eye exam every one to two years.
More frequent exams are generally recommended for:
- Adults 65 and older
- Children and teens (development and screening)
- Contact lens wearers
- Patients with diabetes, hypertension, or a family history of glaucoma or AMD
- Anyone with current symptoms or known eye conditions
If you are unsure of the right interval, your optometrist can advise based on your history and findings.
Related
Due for an eye exam?
A comprehensive eye exam at Spadina Optometry checks both vision and eye health — including tests that detect conditions before symptoms appear.
Prefer to talk first? Call or text us at 416-703-2797.
Last reviewed: February 23, 2026