Vision Test

Our vision, as well as how we use it, differs according to various factors, so the vision test should be framed accordingly.

If we consider the vision test as a test for ocular pathologies, we immediately think of ametropias, we talk about visual acuity, the evaluation of binocular vision and the observation of the fundus of the eye .

The measurement of visual acuity, allows us to quantify our vision. It can be defined as the ability to identify the shape and outline of objects of different sizes at the same distance. 

When measuring visual acuity in the vision test, the patient will be asked to refer to optotypes, which can be letters, numbers or symbols, always at the same distance, varying only in size. The aim is to identify the size up to which the patient can identify the optotypes without effort. It is important to carry out the measurement, without and with correction, with the most recent graduation. We can consider this measurement, and its variation, as a reference test for several pathologies, where it is important to evaluate their evolution and progression.

It also allows to evaluate binocular vision (capacity to unite the two different images received from each eye into only one). The fact that the image taken by the right eye is not exactly the same as the one taken by the left eye, allows the existence of stereoscopic vision (vision in 3 dimensions). The alterations of binocular vision are not always evident, therefore it is necessary, in order to qualify it, an evaluation orthoptic evaluation.

Fundus examination, part of the vision test, is recorded by retinographywhere available.

Worldwide, millions of people have a decrease in visual acuity. Any pathology with repercussions on vision can be related to both ocular and systemic pathologies. 

In terms of ocular pathologies, the main ones are ametropias, a cataract, o glaucoma, a diabetic retinopathy and Age-related Macular Degenerationas in the long term some of these conditions can cause irremediable loss of sight if not treated properly.

As visual acuity can be affected by any of these, vision testing is extremely important not only for the diagnosis and follow-up of the pathology, when therapies are applied, to check whether there is a positive or negative evolution.

In terms of binocular vision, whenever there are alterations, the patient can present some complaints, such as, for example, difficulty concentrating when reading, visual tiredness, headaches after visual effort, dizziness and reduction of three-dimensional vision, among others. Any of these symptoms can be associated to other alterations other than binocular vision, so it is always important to perform screening through vision tests. These symptoms can be associated with convergence insufficiency, amblyopia strabismusamong others.

Fundus examination helps in the diagnosis and follow-up of several clinical pathologies with retinal manifestations, it can find macular and optic nerve alterations and retinal vascular alterations. Besides, it is an examination that helps in the follow-up of some treatments. Not all pathologies with retinal repercussions present symptoms, which reinforces the importance of vision tests.