Funduscopy
The test itself involves no risk. The dilating eye drops may rarely produce nausea, vomiting, dryness of the mouth, flushing, dizziness, or an attack of narrow-angle glaucoma. If the latter is suspected, drops generally are not used.
Ophthalmoscopy is considered to be 90-95% accurate and can detect the early stages and effects of many serious diseases.
Yanoff M, Duker JS, Augsburger JJ, et al. eds. Ophthalmology. 2nd ed. St. Louis, Mo: Mosby; 2004:1461-1462.
Ruamviboonsuk P, Wongcumchang N, Surawongsin P, Panyawatananukul E, Tiensuwan M. Screening for diabetic retinopathy in rural area using single-field, digital fundus images. J Med Assoc Thai. 2005 Feb;88(2):176-80.