FINALLY

Question 1

is a person’s capacity to construct a picture and give it meaning. It includes elements such as visual form recognition, visual memory, spatial interpretation, and visual figure ground.

Answer 1

Visual perception

Question 2

LIST OF VISUAL EFFICIENCY SKILLS (4)

Answer 2

eye teaming
eye movement control
vergence
accommodation

Question 3

It is the capacity of each eye to transmit information to the brain
and for the brain to put the information together so that we receive a single
distinct picture. By default, the information provided from each eye differs
significantly. The brain processes the information to generate a 3D
representation that allows us to evaluate depth, interpret spatial connections,
and more

Answer 3

Eye teaming

Question 4

It is the capacity of both eyes to move together to
point at a specific at a static object or following a dynamic object. It helps us
read a line of print, track a moving ball, adjust focus from far to near smoothly
and efficiently. This is a crucial skill in the classroom where information is
delivered from varying distances.

Answer 4

Eye Movement Control

Question 5

It is the capacity of both eyes to move together in order to focus on
a certain point in space. – Convergence which is needed in all close distance
tasks such as desk work, working on a smartphone or in sports when catching
a ball and Divergence for distance tasks which helps a person when reading
the board at school, driving, and watching TV.

Answer 5

Vergence

Question 6

it is the ability to keep the image clear at different distances,
changing from far to near and vice versa. An example is when you read a text
on the board and then back to your notebook to take down notes. This should
be effortless and adjust focus quickly at distance and near for extended
periods of time

Answer 6

Accommodation

Question 7

TRAINING
➢ Fixate on the clearest visual point, concentrate on a specific area, and
maintain this focus for progressively longer and more stable intervals
➢ Observe an object while practicing the coordination of eye-head-body
movements and maintaining fixation without losing track of the target.
Initially, the movement must be regular and predictable
➢ To load the activity, track objects that move unpredictably and irregularly.

Answer 7

-

Question 8

recognition of differentiating features. distinctions and
similarities, changes of shapes, orientation, and color in objects.

Answer 8

Discrimination:

Question 9

the image is composed by the figure and the background.This ability allows to
prioritize the figure from its background.

Answer 9

Figure-background distinction:

Question 10

from any spatial position and despite the variations
of measure, color, shape, details, etc. Either visualizing it in a real way
or representing it with a drawing or photography.

Answer 10

Shape recognition:

Question 11

this ability allows to recognize an object despite not
having all the details that define it. For example, recognising a car even
if it has no wheels.

Answer 11

Visual closure:

Question 12

storage area in which images are previously preserved
to remember them and to recognise them in different contexts.

Answer 12

Visual memory:

Question 13

it allows direct hand movements with vision.

Answer 13

Eye-hand coordination:

Question 14

this is due to macular
affectation. It is possible to see objects in pieces, twisted or inclined, and they
frequently disappear from their visual field. This occurs because they perform
fixation in the central area, which coincides with the scotoma, and depending
on its characteristics, they present one kind of problem or another.

Answer 14

Loss of central visual field (with central scotoma):

Question 15

it is not possible to visualize an area entirely and,
depending on the visual field loss, it might be impossible to see a full object.
Even when central vision is good, there are problems of location, exploration,
tracking, visual closure, the relation of the parts with the whole and to establish
spatial relations.

Answer 15

Peripheral visual field loss:

Question 16

visual acuity loss
determines how we practice perceptual skills, and they all can be affected to a
greater or lesser extent.

Answer 16

Blurred vision without alterations in the visual field:

Question 17

: the constant movement of the eye causes blurred vision, and
stability must be achieved by learning to compensate for the eye movement to
stabilize fixation and the rest of perceptual skills

Answer 17

Nystagmus

Question 18

CENTRAL FIELD LOSS
The _______is the central area of the retina that allows the maximum visual resolution
and detail discrimination, which is used for reading and doing fine work that requires
detail recognition.

Answer 18

macula

Question 19

is the area responsible for color vision and vision in good lighting circumstances. When a macular pathology appears, this central area of the retina becomes affected, producing a spot known as a scotoma in the central
visual field. For this reason, whatever the patient fixates on will be seen blurry or
distorted depending on the degree of affectation. As the peripheral retina is not
damaged, the ability to perceive bundles and movement remains, without notably
affecting the wandering and detection of obstacles that appear on the road.

Answer 19

macula

Question 20

For this reason, whatever the patient fixates on will be seen blurry or
distorted depending on the degree of affectation. As the peripheral retina is not
damaged, the ability to perceive bundles and movement remains, without notably
affecting the wandering and detection of obstacles that appear on the road.

Answer 20

CENTRAL FIELD LOSS

Question 21

The main pathologies originating central scotomas are macular pathologies, of which
we can highlight:
* Age-related Macular Degeneration (AMD)
* Myopic maculopathy
* Retinal vascular disease
* Macular oedema
* Macular hole
* Macular coloboma
* Stargardt’s disease

Question 22

is the leading cause of blindness in people over 50
years old in developed countries. It is a degenerative disease that appears at 50 years
old and affects the macula causing a central vision loss.

Answer 22

AMD

Question 23

There are two types of AMD:

Answer 23

dry or atrophic type
wet or neovascular type

Question 24

, which is characterized by a slow and progressive evolution
and makes objects look like a blurred spot in the visual center

Answer 24

dry or atrophic type

Question 25

which is characterized by the appearance of choroidal
neovascularization in the macula, producing a severe and quick loss of central vision.

Answer 25

wet or neovascular type

Question 26

Studies indicate that the prevalence of AMD increases with age, the_________
being the less frequent one but responsible for ___ of blindness.

Answer 26

exudative type
80%

Question 27

Methods to solve central field defects:

Answer 27

When looking at an object, in order to see all its details, we use central vision,
performing eye movements to guide the eye in such a way that very specific areas of
the objects are fixated with the fovea. These areas are called fixation points. The
peripheral vision of the retina, even if it is unclear, provides information about the next
fixation point as it decreases VA from the center to the periphery. When there is a
macular pathology, central fixation is affected, and therefore the maximum visual
acuity in such a way that the person must reorient fixation towards another area of the
retina outside the scotoma, allowing to see the object of interest. This new extrafoveal
area is called preferred retinal locus (PRL).
Therefore, eccentric fixation is the term used when damage occurs in the macula and
requires the development of a preferred retinal locus (PRL) near the scotoma that
might be used as a new fovea. When the subject looks in such a way that they are
able to see with the PRL and is aware of it, this is called eccentric vision; however,
when the subject is seeing the PRL but thinks they are looking directly to the object,
this is called eccentric fixation. In this case, we will be looking eccentrically, so the
image is projected in an area of the retina that is not the fovea and it will not be
affected by the scotoma.

Question 28

There are different evaluation methods

Answer 28

● Observation of the head of the patient or movement of the eyes: the patient
does this when we ask some questions or when we take their visual acuity,
indicates the eccentric fixation area that the patient uses. It is a simple and
easy method, although it only does an estimate of the PRL position.
● Visual acuity in different gaze positions: it is performed by indicating the
patient
to look to the upper, lower, left, or right part of an object; or to the letters when
evaluating visual acuity. The patient must indicate at which positions they can
better see the letters. Just as in the observation of a patient’s face, it is easy to
do, but it is also inaccurate.
● Face field:
● Observation of the corneal reflex: this method consists of identifying the gaze
position depending on the location of the corneal reflex of a light point placed
at 75 cm from the person, like the Hirschberg test. If this fixation is foveal, the
reflex that occurs is slightly displaced towards the nose, taking as a reference
the optical axis. If the fixation is performed in the temporal area of the retina, he reflection of the cornea is displaced towards the nasal area and if we
observe that it displaces towards the temporal area it means that it fixates with
the nasal area. This reasoning is identical if it is fixated in upper and lower
positions. This method is imperfect to determine the location of the PRL,
because on occasions it might be unstable, or the patient might fixate in two
simultaneous areas.

Question 29

this is a simple technique that does not require specific equipment
and can be used in daily practice.

Answer 29

Face field:

Question 30

The examination of the ____allows us to determine qualitatively and/or
quantitatively the size, location, and depth of the scotoma.

Answer 30

visual field

Question 31

QUALITATIVE METHODS IN LV

Answer 31

amsler grid
tangent screen

Question 32

QUANTITATIVE LV METHOD

Answer 32

Goldmann perimeter
Static perimeter

Question 33

: the automated evaluation methods of the visual fields exceed most
problems produced through qualitative methods of measure of the visual field. These
techniques are more complex and require the use of a perimeter to perform them

Answer 33

Quantitative METHOD IN LV

Question 34

: it is a test that has a grid of 10cm x 10cm, divided into squares of 5mm
which are equal to 1o of visual field. By keeping the card at about 30 cm from the
patient’s eye, it allows exploring the central 10o. To evaluate the visual field, the
patient is asked (with the best correction and 3 dioptres of addition or
accommodation) to look at the black dot in the center of the grid at the recommended
distance of 30 cm and that by looking at that point, the patient describes the central
area. In case the patient is not able to see the fixation point, they can be shown a new
sheet with diagonal lines crossing in the center. The patient is asked to explain, while
fixating the central black spot, whether they see a blurred or distorted line or any hole
in the area and say if they are able to define the four corners of the grid. In case the
patient perceives a hole, they are asked to delineate the area of the scotoma, and if
there are difficulties to locate the margins, the patient can introduce a trial object of 1
mm to
delineate the exact dimensions of the defect.

Answer 34

Amsler grid

Question 35

The _____ is a quick and easy technique to qualitatively assess the central
visual field and is easy to interpret. However, it has a low sensitivity that is unable to
detect 77% of the scotomas of 6o or less of diameter. The test is being overcome by
other techniques such as the tangent screen in the realm of qualitative tests and
computerized perimeter, although it is not used to evaluate the extent and depth of the
scotoma. However, it is useful for the quick detection of the location of the scotoma in
regard to the fixation point.

Answer 35

Amsler grid

Question 36

The patient is asked to describe the central area of the grid. If the patient is able to
see the point of central fixation, it is possible that they are already using eccentric
vision. It can appear in a patient that presents the defect for a long time and that
instinctively has developed eccentric vision on their own.

Answer 36

evaluation of the scotoma and eccentric vision:

Question 37

Distortion of the central squares: wavy or blurred lines
· Positive scotoma: the patient refers a spot or a cloud
· Absolute negative scotoma: the patient refers that there is no central area
· Relative negative scotoma: the patient refers seeing a blurred area and
usually they don’t require the use of eccentric vision

Question 38

tangent screen is also known as

Answer 38

Bjerrum screen)

Question 39

a fabric of black felt with a
central white point and concentric black circles, located at 1 meter from the patient to
evaluate monocularly central 30o of the visual field. This technique consists of
showing on the screen, a sufficiently large stimulus to be detected in peripheral vision,
using a black rod with a white circle in its end. The patient is asked to be in front of the
screen with the eyes at the height of the fixation point using the adequate prescription
for that distance. This point can be expanded depending on the visual acuity that it
presents. If the fixation is difficult due to a large central scotoma, it can be placed
diagonally with a white rope from the two corners of the tangent screen to guide the
patient towards the intersection of the lines, and the subject is asked to fixate on the
area where they think the lines intersect. Then, the rod goes along a meridian, from
the periphery to the central point, until being detected for the first time, and then the
other way around, starting from a position of the stimulus inside the visual field, in
which it is detected and moves towards the outside area until it stops perceiving it. It
will be repeated throughout every meridian. The points of disappearance and
reappearance are designated with black pins, so they are able to perceive the field
contours or the defect growth as the examination advances. If at any time a defective
area appears, the patient must explore thoroughly to determine in detail the size,
shape, and density of the scotoma. To know if the patient has understood the
instructions, the blind spot will first be analyzed (in this area it is not necessary to
perceive this stimulus).

Answer 39

tangent screen

Question 40

one of the most widely used methods and it shows more
sensitivity in the detection of scotomas than other qualitative methods, such as the
Amsler grid. Compared with the SLO, the results are very similar in regard to shapes,
location and size of scotomas, even when the conditions of the examination and
stimulus (light, background light, etc.) are very different. The tangent screen is
therefore a method that can be very useful in the clinical practice to evaluate
scotomas without the need of an SLO, since it is a very expensive device and it is not
found in all low vision units.

Answer 40

tangent screen

Question 41

the patient must remain seated in front of the perimeter with
one of the eyes occluded. A stimulus of constant size and intensity is projected
throughout a meridian, from the periphery to the center, to determine at which point
the patient begins to perceive the stimulus. By joining all the points in which the
patient has perceived the same stimuli, the isopters determine the different sensitivity
areas. It is later performed in the contralateral eye.

Answer 41

Goldmann perimeter:

Question 42

they are the perimeters used in routine practice to evaluate the
visual field. In this case, a stimulus of variable intensity is projected in prefixed (static)
points inside the region to be explored in the visual field. There are selected
programmes that exclusively evaluate the central field. The goal is to find the
minimum stimulus that is detected in a constant manner by the patient at every point.

Answer 42

Static perimeter:

Question 43

To be able to train eccentric vision to patients with central scotomas, it is important
first to be aware of this scotoma. Many patients are not aware of this defect in their
central visual field, since they do not perceive the object with a black spot in the
center, but this space is “filled” with the environment. The brain must fill that space in
any way; there are no black holes, and there cannot be black holes. It is done with the
most common color of the environment. For example, if the patient is looking at a
white wall and the scotoma occupies the area in which there is a picture, the patient
will fill that hole with the white color surrounding the object. The scotoma is like the
one caused by the optical nerve, which makes visual rehabilitation more difficult. Only
on specific occasions with lack of visual stimuli are they able to perceive the black
spot of the scotoma. A valuable application of the information obtained through the
evaluation of eccentric vision is to be able to teach patients to be aware of the
extension of the scotoma, since the difficulty to stabilize eccentric fixation is the lack of
consciousness.
There are many patients that spontaneously develop a PRL (Preferred Retinal Locus),
while others do not have enough ease or capacity to achieve it. Or it is possible that
the area where it is located is unfavorable and because of this, it presents lower visual
acuity than what the patient could have and lots of difficulties performing pursuit and
saccadic eye movements.
The objective of training is to improve the residual sight of the patient, making it as
functional as possible to be able to do the daily tasks and thus improve quality of life.
Once the retina has been evaluated and the characteristics of the scotoma are known
(location, size and density), it is possible to establish a PRL, with training, that can
keep fixation and eye movements. The visual aids of magnification such as
magnifiers, microscopes or telescopes are instruments that optimize the visual
efficiency by enhancing the residual sight, but they are secondary aids if the patient
cannot stabilize fixation.
The training of eccentric vision can be an adequate initial treatment that can be done
to everyone that present central scotomas, it is not only indicated for those who have
reading difficulties, but it can be also beneficial to perform daily tasks, such as
introducing the key in the lock or finding the fork in the table. To start the training, the
patient must know and understand the importance of it, and we must be sure that the
patient will be able to perform the task. There are studies that justify that with time and
training, the patient can fixate eccentrically.
The muscles of the eye are strengthened to direct our gaze to the front (primary
position). As a central scotoma appears, fixation acts as a reflex over it, impeding
sight of the objects or appears as incomplete, blurry, twisted or inclined.
To avoid these difficulties, they must find an area that provides a healthy space as
wide as possible and, at the same time, close to the macula. In other words, use an
eccentric vision.
The modification of the gaze position can be applied to many tasks: seeing better the
face of a relative, locate with greater ease the light of a traffic light, etc.
Keeping eccentric vision is not an easy task and alters the efficiency in the use of
skills, such as location, pursuit, and exploration. The eye muscles are not prepared to
modify the fixation point and suffer the same effects as patients who perform a
physical activity without training.
The need to perform a fixation change will depend on the type of scotoma and the
learning of fixation that the individual has previously done. Training is useful when
There are absolute negative or positive scotomas of great size

Question 44

Training must contemplate two aspects:

Answer 44

• Take awareness of the existence of a “new way of looking”. Direct the eyes in a
  different way from the primary position, with the purpose of “seeing” the object and not
  necessarily “looking at it”.
• Creation of a false macula (use of eccentric vision). After knowing the possibility of
  seeing in another way, the nearest area to the macula should be located (with better
  vision), trained and maintained with different situations and activities.

Question 45

It will influence the intensity of the scotoma (if it is _____), the size or the
area of the visual field where it can be found.

Answer 45

relative or absolute

Question 46

training phases of eccentric vision

Answer 46

static phase
dynamic phase

Question 47

Static phase: location and maintenance of eccentric vision:
o Location of eccentric vision: with some of the methods that we have
previously seen.
o Training: practice eccentric vision in the home for short periods of time trying
to strengthen and consolidate it. It is possible to use the TV, a picture, a vase,
etc. Training will continue until being able to perform it almost automatically,
without feeling discomfort (itching, stinging) and in a lasting manner.
o Types of activities:
▪ The patient should be in front of the TV with programmes that show
close-ups and in which there is an absence of images in movement (e.g., the
news). The subject should practice on the new gaze position for a minute,
repeating it several times a day. It is possible to use a post-it that should be
stuck to the TV in the area in which we have agreed that there is eccentric
vision.
▪ Repeat the exercise later with smaller objects like pictures, points of light,
etc.
▪ Repeat the exercise throughout the day and in different situations until
locating the PRL automatically.

Question 48

• Dynamic phase:
  o Follow-up with eccentric vision: the objective is the use of eccentric vision to follow
  objects and people in motion. At the beginning, the patient will be standing and then
  moving. The patient can use the movement of any relative while walking, or the
  movement of vehicles driving slowly, etc. Eccentric vision must be kept as long as
  possible, abandoning when pain is felt in the eye. It is better to start in small spaces
  such as a table, looking at a ball rolling with the new gaze position. When this
  exercise is performed easily, the patient will have a larger space and will be able to
  see rolling a ball in a room. The subject will follow it with eccentric vision and they will
  catch it when it stops. After that, we would go on to see friends walking, moving
  vehicles, etc. The patient will remain standing in all exercises and they will only be
  able to move their head, trying to keep the new gaze position. Only when the subject
  dominates these exercises in a static way, will they be able to do the exercises in
  motion.

Question 49

Hand-eye coordination with eccentric vision: all previous exercises, which seek to
strengthen eye muscles should also be used to consolidate hand-eye coordination
with eccentric vision. To do this, the subject will try to pick up things that are close to
them, using the new gaze position. The main objective is to make the patient aware
that there is a new way of looking that allows to use the non-damaged vision areas,
allowing to do daily tasks and recovering reading skills (this matter will be explained
below).

Question 50

: the systematic exploration of the environment is the only way to
obtain correct visual information, and the most efficient way to do it is through
eye movements. Activities can be done with different materials and in different
environments.

Answer 50

Exploration

Question 51

o Establishing the limits of the visual field: the student must know the
repercussion that the field reduction has, as well as the influence of the size
and distance at which objects are placed. The patient must be aware of the
things that “fit” within their visual field in only one fixation and when should the
patient put into practice exploratory movements.
o Effect of the eye’s movement: the functionality obtained will be revealed
when the eyes move carefully and the environment is closer to the static visual
field.
o Exploration of limited areas: the student should explore them with the aim of
not losing detail, making eye movements.
o Exploration in motion: developing effective patterns of exploration as the
patient walks, first slowly and then at their standard pace.

Question 52

The training exercises that can be done are those proposed for developing the
exploration ability. During training, the student will keep and stabilize fixation. This
requires a lot of effort, but with practice the periods are increasingly longer.
* Perception: while the exploratory movements are practiced, this will affect
purely perceptual skills to:
o Interpret everything through a part: “take” each one of the pieces that the
patient can see and identify its corresponding place, to arrive at the correct
interpretation of what the subject is seeing.
o Develop visual memory: by searching it, the patient will be able to process
and give a meaning to the parts of the object that are being
seen.

Question 53

To perform any visual task, it is necessary to use different visual skills. For example,
what level of involvement does each skill have pedestrians see a green traffic light
signaling to cross the street?
In addition to aspects purely related to visual capacity (adequate visual acuity
depending on the distance, good chromatic vision, lighting control, etc.), the following
is necessary:
● To visually locate the traffic light, doing a horizontal scan, since the post is
arranged vertically (exploration, location).
● To look towards the post so the image is projected in the best area of the
retina (fixation).
● To follow the located part, with the eyes or the head, across the post, keeping
fixation, until finding the screen that informs of the status of the traffic light
(fixation and tracking).
● To interpret the image totally, the image provides the information, although the
only a part of the icon or figure can be seen (visual closure).
● To recognise the defining and unique characteristics of the traffic light (visual
memory).

Question 54

figure
(________) and the background (which is
_________).

Answer 54

central element or focus of attention

perceived as imprecise and undifferentiated