Understanding Dry Eye Syndrome — What's Really Going On?

If your eyes feel gritty, tired, or occasionally blurry by the end of the day, you're not imagining it. Dry eye syndrome is one of the most common eye conditions we see at Spectacle — and also one of the most frequently dismissed as "just a bit of tiredness." But there's a great deal more to it than that.

What Is the Tear Film?

Your tears aren't simply salty water. They form a remarkably complex three-layer structure:

The mucin layer — produced by goblet cells in the conjunctiva, this helps the tear film spread evenly across the eye
The aqueous layer — the watery middle layer produced by the lacrimal gland, carrying oxygen and nutrients to the cornea
The lipid layer — produced by the meibomian glands along the eyelid margins, this oily outermost layer slows evaporation

When any of these layers is disrupted, the tear film becomes unstable. That instability is what we call dry eye disease.¹

Two Main Types of Dry Eye

Evaporative Dry Eye (the most common)

In around 80% of cases, the problem lies with the meibomian glands.² These tiny glands — there are around 25–30 in each eyelid — produce the lipid layer of the tear film. When they become blocked or begin producing thickened, poor-quality oil, the protective lipid layer breaks down and tears evaporate too quickly.

This is called meibomian gland dysfunction (MGD), and it's what we're investigating when we use our in-practice meibography imaging to photograph the gland structure directly.

Aqueous Deficient Dry Eye

Less commonly, the lacrimal gland produces insufficient aqueous (watery) tears. This can be associated with autoimmune conditions such as Sjögren's syndrome, certain medications including antihistamines and antidepressants, or simply age-related gland changes.

Many patients have a combination of both.

Why Does It Get Worse in the Evening?

A common pattern we hear is: "My eyes are fine in the morning but by 3pm I can barely keep them open." This makes sense physiologically.

Blinking distributes the tear film across the eye. During focused near tasks — reading, screens, driving — our blink rate drops from a natural 15–20 times per minute down to as few as 5–7 times.³ Over hours, this leads to progressive tear film destabilisation, surface dryness, and the gritty, tired sensation many patients describe.

What We Look For at Spectacle

When you come in with dry eye symptoms, we don't just ask "are your eyes dry?" We assess:

SPEED questionnaire — a validated scoring tool that quantifies symptom severity⁴
Tear break-up time (TBUT) — how quickly your tear film destabilises after a blink
Meibomian gland evaluation — expressing the glands to assess oil quality and flow
Meibography — infrared imaging to assess gland structure and identify any dropout
Lid margin assessment — looking for lid margin disease, telangiectasia, or poor lid seal
Staining — fluorescein and lissamine green dyes to identify surface damage

This comprehensive picture is what allows us to offer genuinely targeted treatment rather than simply recommending whichever eye drops happened to be on promotion.

The Spectacle Approach to Treatment

Treatment depends entirely on what we find. For meibomian gland dysfunction, this may include:

OptiLight IPL — intense pulsed light therapy targeting the abnormal blood vessels (telangiectasia) that contribute to lid margin inflammation. This is currently the only FDA-approved device treatment for dry eye due to MGD⁵
ZEST treatment — a gentle exfoliation procedure targeting Demodex mite infestation, a surprisingly common and underdiagnosed contributor to dry eye
Omega-3 supplementation — evidence-based nutritional support for tear film quality⁶
Preservative-free drops — selected to match the specific deficiency, not just generic lubrication

A Condition Worth Taking Seriously

Dry eye is a chronic, progressive condition. Left unmanaged, meibomian gland dropout — once it occurs — is irreversible.⁷ The gland tissue that is lost doesn't come back. This is why early diagnosis and consistent management genuinely matters, rather than waiting until symptoms become severe.

If you've been managing on over-the-counter drops for months without real improvement, or if you notice symptoms are affecting your work or quality of life, it's worth booking a dedicated dry eye assessment.

We offer dry eye consultations from £80, with imaging and a full personalised treatment plan.

Danish Sheikh BSc(Hons) MCOptom DipTp(IP) is an independent prescribing optometrist and dry eye specialist at Spectacle, Claygate, Surrey. He holds a postgraduate diploma in therapeutics and independent prescribing, and completed specialist training in OptiLight IPL therapy.

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Lemp MA, et al. Distribution of Aqueous-Deficient and Evaporative Dry Eye in a Clinic-Based Patient Cohort. Cornea. 2012;31(5):472–478. ↩
Schlote T, et al. Marked reduction and distinct patterns of eye blinking in patients with moderately dry eyes during video display terminal use. Graefes Arch Clin Exp Ophthalmol. 2004;242(4):306–312. ↩
Ngo W, et al. Psychometric properties and validation of the Standard Patient Evaluation of Eye Dryness questionnaire. Cornea. 2013;32(9):1204–1210. ↩
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Molina-Leyva I, et al. Efficacy of Dietary Supplementation with Omega-3 Fatty Acids in Dry Eye Syndrome. Nutrients. 2017;9(9):1000. ↩
Pult H, et al. Meibomian Gland Loss: The Primary Parameter for Grading Meibomian Gland Dysfunction. Cornea. 2013;32 Suppl 1:S59–S64. ↩