# General Eye Examination Source page: https://www.kudretgozistanbul.com/en/treatments/general-eye-examination **Author:** Kudret Eye İstanbul | **Medical Approval:** Op. Dr. Mehmet Ali Özdil | **Date:** 2026-09-05 > **Summary:** A general eye examination is a comprehensive check in which visual acuity, refraction, eye pressure, the front and back of the eye and, where needed, the cornea, retina and visual field are assessed in one session. Repeated regularly, even without complaints, it lets silently progressing diseases such as glaucoma be caught early. ## Quick Facts - **Duration:** 15-30 minutes; longer if the pupil is widened, to let the drops work - **After pupil dilation:** Near vision blurred and light sensitivity for a few hours; do not drive - **Adults without symptoms:** Every 2 years up to the age of 40, once a year after that - **Child screening:** From six months of age - **Prescription validity:** Usually two years --- ## Which Tests Are Done? Tests build on one another and are read together; not all are done at every visit. Symptoms, age and first findings decide what is added. - **Visual acuity:** reading a letter chart; the only measurement showing how the eye performs now. Reduced acuity can come from the prescription, the cornea or the retina. - **Refraction:** myopia, hyperopia and astigmatism measured automatically as a starting point, then refined to the clearest value; current glasses read on a separate device to see whether anything changed. - **Eye pressure:** measured even without complaints, with a non-contact puff of air and no drops; raised pressure can silently damage the optic nerve. Glaucoma caught early can be halted; lost vision does not come back. - **Slit lamp examination:** eyelids, cornea, anterior chamber and lens; shows cataract, dry eye, corneal clouding and inflammation. - **Corneal mapping:** curvature, thickness and regularity; shows irregular astigmatism that glasses cannot correct, laser suitability and early keratoconus. - **Tear film and eyelid assessment:** tear stability and oil gland function; explains burning and fluctuating vision, and dry eye must be treated before laser surgery. - **Dilated examination:** retina and optic nerve where needed; finds retinal tears, macular disease and diabetic changes. - **Retinal imaging (OCT):** micron-level cross sections showing fluid, thinning and swelling; repeated to judge treatment response. - **Fundus photography:** colour photos of retina, macula and optic nerve, valuable for year-to-year comparison. - **Visual field:** maps peripheral loss; cornerstone of glaucoma diagnosis and follow-up. - **Corneal cell count:** endothelial cells keep the cornea clear and do not regenerate; shows the risk of corneal clouding before cataract or lens surgery. - **Screening in children:** a handheld screener measures both eyes from a metre away in seconds, detecting prescription differences between the eyes, squint signs and lazy eye risk; usable from six months of age. ## Technologies & Devices Used - **KR-800:** automatically measures refractive power and corneal curvature; the first reading for the prescription. - **CL-300:** computerised lensmeter reading current glasses: power, astigmatic axis, UV protection, multifocal lenses. - **TX-20:** non-contact tonometer measuring eye pressure with a puff of air, no drops; warns when pressure is high. - **Vision Screener V100:** handheld screener measuring both eyes from one metre in seconds, from six months of age to adulthood. - **Pentacam:** rotating Scheimpflug camera building a three-dimensional map of the front and back corneal surface for laser suitability, lens calculation and keratoconus follow-up. - **CA-800:** corneal topographer that also measures tear film, meibomian glands and pupil response to light. - **SP-1P:** specular microscope counting corneal endothelial cells. - **DRI OCT Triton:** swept-source OCT at 1,050 nm reaching down to the choroid, also producing a colour fundus photo; used for macular disease, glaucoma and diabetic changes. - **SPECTRALIS HRA+OCT:** combines confocal scanning laser ophthalmoscope and OCT; angiography and autofluorescence on the same machine. - **CF-60DSi:** fundus camera with a 60-degree field; also fluorescein angiography. - **Humphrey Field Analyzer:** measures the visual field; can show glaucoma loss years before the patient notices. ## How Often Should You Be Examined? - Adults without symptoms: every 2 years up to the age of 40, once a year after that. - After forty, with a family history of glaucoma, or with diabetes: more frequent check-ups, as the condition can progress without warning. - Children: an examination before school age, since amblyopia and refractive errors may go unnoticed without complaint. ## Prices The price varies with the tests performed and the examination process and is determined by the ophthalmologist. --- ## The Examination Journey ### 1. Before the Visit - Bring your glasses, earlier prescriptions and a list of regular medicines; mention previous eye surgery or eye drops. - Contact lens wearers may need to leave lenses out for a period that depends on lens type; ask when booking. ### 2. During the Visit - Visual acuity, autorefractometer, eye pressure and slit lamp, then pupil dilation where needed and further tests (corneal mapping, visual field, OCT) depending on symptoms. ### 3. After the Visit - After dilation, near vision is blurred and light sensitivity lasts a few hours: do not drive, bring sunglasses and preferably a companion. ## Understanding Your Prescription - **Sphere (SPH):** main correction; minus (−) for difficulty seeing far, plus (+) for near; larger number means stronger prescription. - **Cylinder (CYL):** astigmatism correction; blank means none. - **Axis:** direction of astigmatism, an angle between 0 and 180 degrees. - **Addition (ADD):** extra near power, usually needed after 40, usually the same for both eyes. - **Prism:** helps the eyes align; only for double vision or squint. --- ## Frequently Asked Questions **Q: What are refractive errors and how are they diagnosed?** A: Myopia, hyperopia, astigmatism and presbyopia, caused by the eye not focusing light correctly. They are found with simple tests during an eye examination and may be suspected from headaches and eye strain; glasses, contact lenses or laser surgery correct them. **Q: What tests are done in a general eye examination?** A: Visual acuity, intraocular pressure, colour vision and eye muscle function tests, with further tests if the ophthalmologist considers them necessary. **Q: Can colour blindness be treated?** A: It is genetic and cannot be cured, but special glasses and filters help colour discrimination.