NBEO PART 1 ACTUAL EXAM QUESTIONS WITH
ANSWERS 2025/2026 GRADED A+|verified 100%
correct|
In addition to the meibomian glands which other accessory glands secrete oil?
Zeiss and Moll
Moll and Krause
Zeiss and Wolfring
Wolfring and Krause - ANSWER -The glands of Zeiss and Moll are accessory oil
glands located on the lid margins adjacent to the base of the lash follicles. The lipid
layer of the tear film is superficial and as such it is exposed to the environment
protecting the aqueous layer from evaporation.
The glands of Wolfring and Krause are located deep in the fornix of the eyelids
and serve to secrete a portion of the aqueous layer of the tear film.
Dacryoadenitis refers to an inflammation or infection of which of the following
ocular structures?
The nasolacrimal sac
The lacrimal sac
The lacrimal gland
The puncta - ANSWER -Dacryoadenitis describes inflammation of the lacrimal
gland, generally due to infection. The swelling is categorized as either chronic or
acute. Acute presentations appear more commonly as a unilateral swelling of the
upper eyelid, along with pain, excessive lacrimation, probable ipsilateral
lymphadenopathy, and potential proptosis. If the condition is bilateral it is likely
due to a systemic infection. Chronic dacryoadenitis is generally bilateral and
presents with hard masses that are palpable at the location of the lacrimal gland.
This form is often painless and caused by inflammatory diseases such as Grave's,
Sjogren's, or sarcoidosis. The chronic type warrants further investigation in order
to rule out a lacrimal gland tumor.
, Chronic blepharitis, if left untreated, can cause which of the following structural
changes to the anterior ocular segment?
Hypertelorism
Distichiasis
Tristichiasis
Madarosis - ANSWER -Blepharitis is a condition caused by pathogens, usually of
Staphylococcus origin, that colonize along the eyelid margins. The bacteria
produce exotoxins which take the form of flakes and are generally seen along the
base of the eyelashes. Unfortunately, this condition is chronic but will wax and
wane in its presentation. Long-term complications include madarosis (missing
lashes), trichiasis, neovascularization of the eyelid margin, keratitis, erythema,
phlyctenule formation and infiltrates. Patients may complain of dry, irritated eyes,
stinging, pain, itching, frequent eye infections, foreign body sensation, and
decreased acuity (if there is corneal involvement). Treatment includes eye lid
scrubs, antibiotic ointments and sometimes transient topical steroid use to decrease
lid inflammation (usually used in conjunction with a topical antibiotic).
Occasionally oral antibiotics are prescribed, especially in the event of poor
compliance.
Distichiasis is a rare congenital phenomenon marked by an absence of meibomian
glands. In the place of the meibomian glands is an extra row of eyelashes.
Hypertelorism is a term used to describe the incidence in which the orbits are
located quite far apart. This generally occurs along with other congenital cranium
anomalies.
Tristichiasis is a very rare occurrence in which a person possesses three rows of
eyelashes.
Ptosis can be caused by dysfunction or damage to which of the following
muscles?
Inferior rectus
Muscle of Horner
Superior tarsal muscle (muscle of Muller)
,Pars ciliaris (Riolan's muscle) - ANSWER -Ptosis is a condition in which the upper
eyelid sags. It can be caused by dysfunction of either the superior palpebral levator
or the superior tarsal muscle (muscle of Muller). Because the levator is the major
muscle responsible for raising the upper eyelid, ptosis from levator damage is often
more severe then ptosis from dysfunction of the muscle of Muller.
The muscle of Horner (also known as the pars lacrimalis) is part of the palpebral
portion of the orbicularis oculi. The fibers for the muscle of Horner come from the
lacrimal crest and encircle the lacrimal canaliculi. This assists the flow of tears into
the nasolacrimal drainage system when the orbicularis oculi contracts to close the
eye. The muscle of Riolan (also known as the pars ciliaris) is another section of the
palpebral portion of the orbicularis oculi; it lies near the lid margin to maintain the
margins next to the globe. The orbicularis oculi is the major muscle responsible for
closing the eyelids.
Tear volume in a normal, healthy, young adult measures approximately between
which of the following values?
13.0-16.0 microliters
6.0-8.0 microliters
17.0-20.0 microliters
2.0-5.0 microliters
9.0-12.0 - ANSWER -Tear volume has been measured by several methods to be
approximately 6-7 microliters in normal individuals, with lesser values occurring
in conditions of aqueous tear deficiency. This has implications for drug delivery,
since the normal ophthalmic drop volume varies between 25 and 50 microliters,
effectively overwhelming the native tear value upon instillation.
The lymphatic system serves many important roles in the human body. The lateral
portion of the eyelid lymphatics drain into which of the following structures?
The puncta
The conjunctiva
The submandibular lymph node
The pre-auricular lymph node - ANSWER -The lateral 2/3 of the upper lid and the
lateral 1/3 of the lower lid lymphatics drain into the pre-auricular lymph node
located directly in front of the ear. The medial 1/3 of the upper eye lid and the
, medial 2/3 of the lower lid lymphatics drain into the submandibular node located
just under the jaw-line. Therefore, it is very important to evaluate these two nodes
separately, especially when a condition of viral etiology is suspected.
A 2.5x Galilean telescope has a -25D ocular lens. When focused for infinity, what
is the length of the telescope?
5 cm
4 cm
6 cm
10 cm
14 cm - ANSWER -M = -Doc/Dobj where Doc=power ocular; Dobj= power
objective; t= separation of lenses
2.5= - (-)25/Dobj
Dobj= 10D
t= f'obj + f'oc
f'obj=1/10D = 0.10 m
f'oc = 1/-25D = 0.04 m
t=0.10 + -0.04 = 0.06 m or 6 cm
10 cm - incorrect- would come up with this ANSWER if only took in account the
focal length of the objective lens.
4 cm - incorrect- would come up with this ANSWER if only took in account the
focal length of the ocular lens.
14 cm - incorrect - would come up with this ANSWER if thought equation was t=
f'obj + f'oc
A patient is using a stand magnifier of +16D with a +2.00 add. If the distance
separating the two lenses is 25 cm what is the equivalent power of this
combination?
10D
18D
26D
22D - ANSWER -De= D1+D2 -tD1D2 where De=equivalent power;D1=power of
magnifier;D2=power add;t=separation in meters between the lenses
ANSWERS 2025/2026 GRADED A+|verified 100%
correct|
In addition to the meibomian glands which other accessory glands secrete oil?
Zeiss and Moll
Moll and Krause
Zeiss and Wolfring
Wolfring and Krause - ANSWER -The glands of Zeiss and Moll are accessory oil
glands located on the lid margins adjacent to the base of the lash follicles. The lipid
layer of the tear film is superficial and as such it is exposed to the environment
protecting the aqueous layer from evaporation.
The glands of Wolfring and Krause are located deep in the fornix of the eyelids
and serve to secrete a portion of the aqueous layer of the tear film.
Dacryoadenitis refers to an inflammation or infection of which of the following
ocular structures?
The nasolacrimal sac
The lacrimal sac
The lacrimal gland
The puncta - ANSWER -Dacryoadenitis describes inflammation of the lacrimal
gland, generally due to infection. The swelling is categorized as either chronic or
acute. Acute presentations appear more commonly as a unilateral swelling of the
upper eyelid, along with pain, excessive lacrimation, probable ipsilateral
lymphadenopathy, and potential proptosis. If the condition is bilateral it is likely
due to a systemic infection. Chronic dacryoadenitis is generally bilateral and
presents with hard masses that are palpable at the location of the lacrimal gland.
This form is often painless and caused by inflammatory diseases such as Grave's,
Sjogren's, or sarcoidosis. The chronic type warrants further investigation in order
to rule out a lacrimal gland tumor.
, Chronic blepharitis, if left untreated, can cause which of the following structural
changes to the anterior ocular segment?
Hypertelorism
Distichiasis
Tristichiasis
Madarosis - ANSWER -Blepharitis is a condition caused by pathogens, usually of
Staphylococcus origin, that colonize along the eyelid margins. The bacteria
produce exotoxins which take the form of flakes and are generally seen along the
base of the eyelashes. Unfortunately, this condition is chronic but will wax and
wane in its presentation. Long-term complications include madarosis (missing
lashes), trichiasis, neovascularization of the eyelid margin, keratitis, erythema,
phlyctenule formation and infiltrates. Patients may complain of dry, irritated eyes,
stinging, pain, itching, frequent eye infections, foreign body sensation, and
decreased acuity (if there is corneal involvement). Treatment includes eye lid
scrubs, antibiotic ointments and sometimes transient topical steroid use to decrease
lid inflammation (usually used in conjunction with a topical antibiotic).
Occasionally oral antibiotics are prescribed, especially in the event of poor
compliance.
Distichiasis is a rare congenital phenomenon marked by an absence of meibomian
glands. In the place of the meibomian glands is an extra row of eyelashes.
Hypertelorism is a term used to describe the incidence in which the orbits are
located quite far apart. This generally occurs along with other congenital cranium
anomalies.
Tristichiasis is a very rare occurrence in which a person possesses three rows of
eyelashes.
Ptosis can be caused by dysfunction or damage to which of the following
muscles?
Inferior rectus
Muscle of Horner
Superior tarsal muscle (muscle of Muller)
,Pars ciliaris (Riolan's muscle) - ANSWER -Ptosis is a condition in which the upper
eyelid sags. It can be caused by dysfunction of either the superior palpebral levator
or the superior tarsal muscle (muscle of Muller). Because the levator is the major
muscle responsible for raising the upper eyelid, ptosis from levator damage is often
more severe then ptosis from dysfunction of the muscle of Muller.
The muscle of Horner (also known as the pars lacrimalis) is part of the palpebral
portion of the orbicularis oculi. The fibers for the muscle of Horner come from the
lacrimal crest and encircle the lacrimal canaliculi. This assists the flow of tears into
the nasolacrimal drainage system when the orbicularis oculi contracts to close the
eye. The muscle of Riolan (also known as the pars ciliaris) is another section of the
palpebral portion of the orbicularis oculi; it lies near the lid margin to maintain the
margins next to the globe. The orbicularis oculi is the major muscle responsible for
closing the eyelids.
Tear volume in a normal, healthy, young adult measures approximately between
which of the following values?
13.0-16.0 microliters
6.0-8.0 microliters
17.0-20.0 microliters
2.0-5.0 microliters
9.0-12.0 - ANSWER -Tear volume has been measured by several methods to be
approximately 6-7 microliters in normal individuals, with lesser values occurring
in conditions of aqueous tear deficiency. This has implications for drug delivery,
since the normal ophthalmic drop volume varies between 25 and 50 microliters,
effectively overwhelming the native tear value upon instillation.
The lymphatic system serves many important roles in the human body. The lateral
portion of the eyelid lymphatics drain into which of the following structures?
The puncta
The conjunctiva
The submandibular lymph node
The pre-auricular lymph node - ANSWER -The lateral 2/3 of the upper lid and the
lateral 1/3 of the lower lid lymphatics drain into the pre-auricular lymph node
located directly in front of the ear. The medial 1/3 of the upper eye lid and the
, medial 2/3 of the lower lid lymphatics drain into the submandibular node located
just under the jaw-line. Therefore, it is very important to evaluate these two nodes
separately, especially when a condition of viral etiology is suspected.
A 2.5x Galilean telescope has a -25D ocular lens. When focused for infinity, what
is the length of the telescope?
5 cm
4 cm
6 cm
10 cm
14 cm - ANSWER -M = -Doc/Dobj where Doc=power ocular; Dobj= power
objective; t= separation of lenses
2.5= - (-)25/Dobj
Dobj= 10D
t= f'obj + f'oc
f'obj=1/10D = 0.10 m
f'oc = 1/-25D = 0.04 m
t=0.10 + -0.04 = 0.06 m or 6 cm
10 cm - incorrect- would come up with this ANSWER if only took in account the
focal length of the objective lens.
4 cm - incorrect- would come up with this ANSWER if only took in account the
focal length of the ocular lens.
14 cm - incorrect - would come up with this ANSWER if thought equation was t=
f'obj + f'oc
A patient is using a stand magnifier of +16D with a +2.00 add. If the distance
separating the two lenses is 25 cm what is the equivalent power of this
combination?
10D
18D
26D
22D - ANSWER -De= D1+D2 -tD1D2 where De=equivalent power;D1=power of
magnifier;D2=power add;t=separation in meters between the lenses
