It is a common misconception that 20/20 vision = Healthy eyes. However this is not necessarily the case. There are a many eye conditions and diseases that can affect or damage the eye and at least in the early stages the patient can still maintain “20/20 Vision.”
True or False? You don’t need an eye exam if you have 20/20 vision.
Answer: False.
Although 20/20 is a good start, it in no way guarantees that your eyes are healthy. Below is a review of the most common eye conditions and diseases that can occur with “20/20 Vision.”
Amblyopia
Amblyopia is a condition where the eye never develops 20/20 vision due to an uncorrected prescription, a misalignment of the eyes or some other eye disease that affects central vision or acuity. If this occurs in one eye only, a person may still have 20/20 vision overall all with the use of both eyes but have a severe deficiency in the sight of the amblyopic eye. This is not uncommon, particularly in children. Children often don’t know how well they should see and therefore assume that their vision is normal despite a glaring visual problem. Many types of amblyopia can be improved with treatment but the key is early detection.
Glaucoma
Glaucoma is a disease where the intraocular pressure in the eye starts to damage the Optic nerve (the nerve that connects the eye to the brain). With glaucoma the intraocular eye pressure is usually elevated but in some patient, glaucoma can even occur at what is considered “normal eye pressure”. Over time, the Optic nerve becomes more and more damaged with the end result being loss of vision potentially to the point of blindness. The most common type of Glaucoma, called Open Angle Glaucoma, has no symptoms in the early stages. It is painless and the damage to the nerve occurs gradually, silently and slowly stealing your vision. Damage from glaucoma typically starts with the peripheral vision and progresses inward leaving the central vision until last. Therefore a patient can have advanced glaucoma and still maintain 20/20 central vision. Unfortunately, once the damage occurs it is permanent. Although glaucoma is not curable it is treatable. Once again the key is early detection with regular eye exams. Glaucoma testing is part of every comprehensive eye exam we perform.
Diabetic Retinopathy
Diabetes is the leading cause of blindness in the United States. Surprisingly, most cases of blindness from diabetes are largely preventable if the problems are detected and treated early. Diabetic retinopathy is the result of the elevated blood sugar damaging the lining of the blood vessels that nourish the retina (the part of the eye that you see with). Over time these vessels start to leak and produce swelling in the retina and as the condition progresses can lead to more advanced damage that can cause permanent scarring and even retinal detachment and total loss of vision. Often, unless the changes occur in the central vision, the patient can maintain 20/20 vision despite serious retinal problems. Therefore it is important for every patient with diabetes be seen on a regular basis. The frequency of visits can range from annually to every few months depending on the health of the eye, the control and duration of the diabetes. Our office monitors many patients with diabetes and corresponds regularly with their diabetes doctor about their care and status.
Peripheral Retinal Diseases and Degenerations
Peripheral retinal conditions can be present without symptoms and because they are in the periphery the patient could likely have 20/20 vision. However their presence indicates significant risk factor for progression to retinal tears or detachments. Only a thorough eye exam including pupil dilation can detect many of these types of conditions. Once detected, they can be managed or treated appropriately.
Macular Degeneration
Macular degeneration is disease that affects central vision. It is most common in patients over 50 years old with the risk increasing with age. Macular degeneration affects the part of the retinal responsible for central vision called the macula. Over time it develops deposits and degenerative aging changes that affect its function. In the early stages of Macular degeneration, a patient may still have 20/20 vision but in more advanced stages the central vision becomes reduced. Although, macular degeneration is not curable there are several risks factors that can be addressed to possibly slow down its progression. It is also important to monitor patients with macular degeneration for the potential sight threatening development of “wet” macular degeneration. Although “wet” macular degeneration can lead to more severe vision loss there have been some advances in recent years with treatment options that potentially can limit the damage that occurs. Once again, early detection is key.
