It is fairly easy for you or your charge to check vision on a daily basis, one eye at a time. Using proper lighting and preferably in the same fashion each day, a person can check to see that if they can read the same size small print.
An Amsler grid is a graph paper type piece of card that is an excellent test of macular function. While covering one eye at reading distance, the grid can be checked for distortion, waviness, and missing or dark areas. This is a very sensitive test for visual function, but remarkably, there is a group of approximately 11% of patients with known macular disease that report this as being normal. Abnormal results however are quite significant and should prompt an examination.
Not All Eye Disease Causes Visual Symptoms
When there is severe loss of peripheral vision in both eyes, visual function is quickly compromised. However, I have seen patients with advanced glaucoma and loss of the peripheral vision unaware of the condition until they have had several car accidents. Conversely patients with macular degeneration may be rendered legally blind at 20/200 or worse vision due to loss of the critical central portion of the vision used for reading and fine visual tasks yet function quite well.
They frequently cannot identify faces well if the blind spot occupies the center of the vision. Many people with eye problems simply insist that stronger glasses will help them but if the retina, the equivalent of film in the camera is damaged, the most expensive lens system in the world cannot compensate for this.
Mild Visual Symptoms Indicative of Eye Problems
Serious eye problems can bepresent with mild symptoms such as distortion and slight difficulty in reading in one eye. This can indicate the new onset of exudative age-related macular degeneration. This condition can rapidly progress with leaking blood vessels causing expanded loss of the central field of vision almost invariably over a period of one to three months without treatment.
It is not uncommon for the patient to come in with advanced macular degeneration in their non-dominant eye that is unaware of it and only present in the second eye if it becomes involved. With the advent of Lucentis therapy for this condition, which can stabilize 90% of eyes with the wet form of macular degeneration and improve the vision in approximately one third, detection is all the more important. This is especially true with these newer treatments, which work better at the earlier stage of the leaking blood vessels than once the once the condition is further established.