Examining an eye involves a series of tests to assess visual acuity and the health of the eye's structures. It's a multi-step process that checks various aspects of vision and eye health.
Key Aspects of an Eye Examination
A comprehensive eye examination typically includes the following:
1. Visual Acuity
This measures how well you see at various distances. You'll likely be asked to read letters or symbols on a chart (Snellen chart).
2. Pupil Examination
Pupillary response to light is assessed using a penlight. The pupils should constrict (become smaller) when light is shone on them and dilate (become larger) when the light is removed. Often, eye drops are used to dilate the pupils for a more thorough examination of the fundus (the back of the eye). Examine the pupils with a penlight to see if they respond (constrict) properly to light. (Reference 1)
3. Extraocular Motility and Alignment
This checks how well your eyes move and align together. The examiner will assess eye movement in all directions. They may ask you to follow a moving object with your eyes. This section checks if your eyes align properly, and if your eyes move correctly in all directions without moving your head. (Reference 3) Hold your finger (or a pin) approximately 30cm in front of the patient's eyes and ask them to focus on it. Ask the patient to follow your finger as you move it in the different directions of gaze. (Reference 6).
4. Examination of the Front of the Eye
Using a slit-lamp microscope, the examiner will illuminate and examine the eyelids, conjunctiva, cornea, iris, and lens. (Reference 2) The swinging torch test assesses the pupillary response. (Reference 5)
5. Examination of the Fundus (Back of the Eye)
After pupil dilation, the ophthalmoscope is used to examine the retina, optic nerve, and blood vessels at the back of the eye. This allows detection of various conditions. (Reference 1)
6. Intraocular Pressure
This measures the pressure inside your eye, helping detect glaucoma. (Reference 4)
7. Peripheral Vision
This assesses your side vision. (Reference 2)
8. Stereoscopic Vision (3D Vision)
This assesses your ability to perceive depth and three-dimensional images. (Reference 2)
Tools Used in an Eye Examination
- Snellen chart: To measure visual acuity.
- Penlight: To assess pupillary response.
- Ophthalmoscope: To examine the fundus.
- Slit-lamp microscope: To examine the front of the eye.
- Phoropter: To assess refractive errors. (Reference 9)
