During an eye examination, your optometrist in Canberra at Capital Eye performs comprehensive tests to assess vision and overall eye health. These tests are critical for determining whether corrective lenses are needed and detecting eye diseases and other health issues that may arise. Below are the key components typically included in a standard eye examination.
Patient History
The eye examination begins with thoroughly reviewing the patient’s medical history. This includes asking about general health conditions, such as diabetes or hypertension, which can affect eye health. Your optometrist in Canberra would also ask about any medications you are taking, as some drugs could have side effects that may impact your vision. Additionally, your optometrist in Canberra may ask about any specific symptoms you might be experiencing, such as blurred vision, eye fatigue, headaches, eye pain, or flashes of light. Family history is another crucial aspect; conditions like glaucoma, macular degeneration, or retinal detachment can be hereditary.
Visual Acuity Test
One of the most fundamental tests in an eye examination is the visual acuity test. This measures how clearly each eye sees using an eye chart, which typically features rows of letters with decreasing size. The patient is asked to cover one eye at a time and read the smallest line of letters they can see clearly. The results are usually recorded as a fraction, with 20/20 or 6/6 vision considered normal. This test helps determine the sharpness or clarity of vision at a specific distance.
Refraction Assessment
Refraction assessment determines the prescription needed for corrective lenses. The optometrist uses a device called a phoropter, which has multiple lenses. The patient looks through the phoropter at an eye chart, and your optometrist in Canberra changes the lenses by asking the patient which ones make the chart appear clearer. This process helps identify refractive errors such as myopia (nearsightedness), hypermetropia (farsightedness), and astigmatism. An autorefractor or a retinoscope may also provide an initial assessment by measuring how light changes as it enters the eye.
Keratometry/Topography
Keratometry measures the curvature of the cornea, the eye’s outermost surface. This is crucial for fitting contact lenses and diagnosing astigmatism, where the cornea has an irregular shape, causing blurred vision. Corneal topography provides a detailed map of the cornea’s surface, revealing even minor irregularities. This test is especially useful for planning surgeries like LASIK or managing conditions like keratoconus, where the cornea becomes cone-shaped.
Pupil Response
The pupil response test checks how the pupils react to light. By shining a light into the eyes, your optometrist in Canberra observes the size and shape of the pupils and their response to light. This test can reveal neurological issues since abnormal pupil reactions may indicate problems with the optic nerve or the brain.
Eye Movement
Also known as ocular motility testing, this test evaluates how well the eyes move and work together. Your optometrist in Canberra might ask the patient to follow a moving object, such as a pen or a light, with their eyes. This test assesses the functionality of the extraocular muscles, which control eye movement. Issues here can indicate strabismus (crossed eyes), amblyopia (lazy eye), or other binocular vision problems.
Binocular Vision Assessment
Binocular vision assessment tests how well the eyes work together to focus and perceive depth. This is crucial for tasks requiring precise depth perception, like driving or reading. Your optometrist in Canberra might use stereopsis tests, where the patient wears 3D glasses and identifies which part of an image stands out. Poor binocular vision can lead to symptoms like double vision, headaches, and difficulty with eye-hand coordination.
Slit-lamp Examination
A slit-lamp examination involves using a specialised microscope to examine the front part of the eye. The slit lamp emits a thin beam of light, allowing your optometrist in Canberra to view the cornea, iris, lens, and anterior chamber in great detail. This test helps detect various conditions, including cataracts, corneal ulcers, macular degeneration, and diabetic retinopathy. By adjusting the slit lamp, the optometrist can also examine the inner eye structures, providing a comprehensive overview of eye health.
Intraocular Eye Pressure Measurement
Intraocular pressure measurement, often called tonometry, measures the pressure inside the eye. High intraocular pressure could be a sign of glaucoma, a condition that can lead to peripheral vision loss if not treated promptly. The most common method is the “puff-of-air” test, where a small burst of air is directed at the eye to measure resistance. Alternatively, your optometrist in Canberra might use an applanation tonometer, which gently touches the eye’s surface after numbing drops are applied.
Retinal Examination
Also called ophthalmoscopy or funduscopy, retinal examination involves using a unique lens to examine the back of the eye, including the retina, optic disc, and blood vessels. Your optometrist in Canberra might dilate the pupils with eye drops to get a better view. This test can detect retinal detachment, macular degeneration, diabetic retinopathy, and optic nerve issues. The health of the blood vessels in the retina can also provide clues about systemic conditions like hypertension and diabetes.
Visual Field Test
A visual field test assesses peripheral vision, which is the ability to see objects outside the direct line of sight. While looking straight ahead, lights are flashed at the edges of their vision, and they press a button each time they see a light. This test can detect blind spots and areas of reduced vision, which might indicate conditions affecting the optic nerve or brain, such as glaucoma, stroke, or brain tumours.
Color Vision Testing
Colour vision testing checks for colour blindness or deficiencies. The most common method involves Ishihara plates, which are images made up of dots in various colours and sizes. You will be asked to identify numbers or patterns within the dots. Colour vision deficiencies are often genetic, but diseases, medications, or chemical exposure can also cause them.
Additional Tests
Depending on the results of the standard tests, the optometrist might perform additional tests to investigate specific issues further. For instance, if dry eye syndrome is suspected, the Schirmer test measures tear production. If an optic nerve issue is indicated, optical coherence tomography (OCT) might provide detailed images of the retina and optic nerve.
Importance of Regular Eye Exams
Regular eye exams are crucial for maintaining eye health and early detection of potential issues. Many eye conditions, such as glaucoma, diabetic retinopathy, and macular degeneration, do not show symptoms in the early stages but can lead to significant vision loss if untreated. Regular exams can catch these conditions early, providing timely intervention and better outcomes. For children, eye exams are essential for detecting issues that could affect their learning and development, such as amblyopia or refractive errors. Regular eye exams become increasingly important for adults, especially those over 40, as the risk for age-related eye conditions rises.
The Bottom Line
In summary, a comprehensive eye examination involves a series of detailed tests that provide a complete picture of a person’s visual and ocular health. These tests are essential for maintaining good vision and overall health, from assessing visual acuity and determining the need for corrective lenses to checking for serious eye diseases and conditions. Regular eye exams ensure that any issues are detected early and managed effectively, contributing to a better quality of life and long-term eye health. If it has been a while since your last visit to your optometrist in Canberra, make an appointment instantly online through our website. The Team at Capital Eye are dedicated to looking after your vision and eye health.