Changes in vision, changes in the appearance of the eye, or an abnormal sensation or pain in the eye, are the three symptoms indicative of eye disease.
While most eye disease symptoms develop as a result of a problem in the eye itself, sometimes they may be indicative of a problem elsewhere in the body or as a result of an illness that affects several organ systems in the body.
Changes in vision
Changes in vision can include the development of the following symptoms, most of which can be symptomatic of a range of conditions:
- Nearsightedness is caused by an elongation of the eyeball over time, which makes it difficult to clearly see objects far away.
- Farsightedness is caused by the shortening of the eyeball, which makes it difficult to see objects that are close by clearly. Many older people wear reading glasses for this reason.
- Blurry or hazy vision, or loss of specific areas of vision, can affect one or both eyes and is the most common vision symptom. Any sudden changes in vision, or sudden inability to focus clearly, should be a cause of concern. Sudden loss of a specific area (such as central or peripheral) should prompt a visit to an ophthalmologist.
- Double vision means you don’t see a single clear image, but one that appears to repeat itself. Headaches, nausea, a droopy eyelid and misalignment of the eyes are all symptoms that could accompany double vision.
- Floaters are specks or strands that seem to float across the field of vision. These are actually shadows cast by cells inside the clear fluid that fills the eye. They could be harmless, but should be checked out as they could point to something serious such as retinal detachment.
- Loss of vision in someone who was able to see before. This cannot be corrected with glasses or contact lenses. Sometimes surgery is also not an option. Partial vision loss refers to very limited vision, and complete blindness means you cannot see anything, even if you look straight into a bright light.
- Night blindness refers to the inability to see clearly in the dark or adapting to the dark, especially after coming out of a brightly lit environment. This can either be genetically inherited, or be a symptom of an eye disease.
- Impaired depth perception means a person has difficulty distinguishing which of two objects is closer to him or her.
Changes in the appearance of the eye
These symptoms could include, but are not restricted to, the following:
- Redness or swelling of the eyes, which have a bloodshot appearance. The eyes could be watery and itchy as well, depending on the cause, of which there are many (from conjunctivitis, to allergies, to an object in the eye, to name but a few). A discharge from the eyes is also possible.
- Redness and swelling of the eyelid. Eyelash follicles could be inflamed, there could be a stye on the eyelid, or it could be the result of allergies or an injury.
- Cloudy appearance of the eye. These can be symptomatic of cataracts, which occur when a build-up of proteins make the lens of the eye appear cloudy.
- Eyelid twitch. This happens when eyelid muscles spasm involuntarily over a period of time.
- Squint gives the appearance of the eyes not being lined up in the same direction. Even after surgical correction, this condition can reappear.
- Bulging eyes could be a symptom of hyperthyroidism or an auto-immune disorder called Grave’s disease.
- Droopy eyelids can be a sign of exhaustion, ageing, migraines or a more serious medical problem.
Pain in and around the eye
Pain on the surface of the eye is called orbital pain, whereas pain within the eye is called ocular pain.
Ocular pain can be caused by a scratch or slight injury to the cornea of the eye or the presence of a foreign object and often causes redness of the eye. Orbital pain can be sharp or throbbing and go beyond the surface.
Whereas pain in the eye often resolves by itself, it should be a cause for concern if it’s accompanied by vision loss, vomiting, fever, muscle aches, eye bulging and difficulty in moving the eye in certain directions.
Trauma to the eye or surrounding facial areas can also be the cause of pain.
Reviewed by ophthalmologist Dr Viresh Dullabh, MBBCh (Wits) FC Ophth SA (CMSA) MMED (UKZN). September 2018.