An eye test is performed by an ophthalmologist (a medical specialist who deals with eyes) or an optometrist. It consists of a series of tests to assess your vision and your ability to discern objects. Periodical eye examinations are recommended as many eye diseases are asymptomatic. Eye tests can detect blinding eye diseases, ocular manifestations of systemic diseases, sign of tumours or other minor issues like the need to wear a pair of glasses.
Applanation tonometry is used to diagnose glaucoma by measuring pressure needed to flatten a cornea portion, as the tonometer touches the eye. The tonometer can be hand-held or attached to a slit lamp. Local anaesthetic drops will be given prior to the test. Alternatively, puffs of air are blown at each of your eyes, the resistance to the air reflects the pressure in the eyes. The measurement of pressure is obtained using a non-contact tonometer. Corneal and retinal topography can be used to detect scarring and swelling of the cornea or retinal detachment. Fluorescein angiogram involves injection of fluorescein, a dye, into a vein in the arm where it travels through the blood circulation to the eyes and highlights any abnormal blood vessels. Your doctor may also administer eye drops to dilate your eyes for the dilated pupillary examination to examine your retina.
An ultrasound eye test can be carried out to look at the eye’s internal structure. This is helpful to determine length of the eye before a cataract surgery.
An autorefractor is used to determine your ability to focus and produce a readout of your approximate prescription for your glasses. Alternatively, your optometrist may use a retinoscope that bounces a light beam off the back of your eye and back into the instrument to provide an accurate guide to the required prescription. An eye test also consists of a test chart where the optometrist flips different lenses in front of your eyes until you have the clearest vision. Each eye is tested individually as the results can vary between one side to another.
You should check whether you qualify for a free NHS-funded sight test before attending one. People aged under 16 and over 60, or people diagnosed with diabetes and glaucoma are eligible for free eye test. You also qualify if you receive income support or have slightly impaired sight.
You will be asked to remove your contact lenses before the eye examination.
If you are wearing glasses, you should also bring your glasses when you go for an examination as you may be required to wear them.
After your eye test, your doctor will discuss the results with you whether you need any prescription or further investigations. If you need a new pair of glasses, you will be given an NHS optical voucher.
If you are diagnosed with serious eye conditions that may potentially impair your sight, your ophthalmologist will discuss the next steps with you whether you need medications or surgical procedures.
This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Doctify Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. In the event of an emergency, please call 999 for immediate assistance.