A diabetic's annual eye photo catches microaneurysms — laser before vision blurs. Systemic diseases write on the eye — diabetes (retinopathy — annual dilated screening; cataract early; neovascular glaucoma), hypertension (Keith-Wagener grades — AV nicking → hemorrhages → papilledema — malignant), thyroid/Graves (proptosis, lid lag, diplopia — steroids, selenium, decompression), HIV (CMV retinitis — pizza-pie hemorrhagic necrosis — systemic ganciclovir; HAART restores), autoimmune (RA — scleritis/dry eye; sarcoid/TB — granulomatous uveitis; Behcet's — hypopyon), pregnancy (preeclampsia — hypertensive retinopathy; central serous — stress). The eye exam is a systemic review — vessels, lids, and retina report the body.