Sharp Edge Eye Syndrome (SEES): A Case Report and Survey of Self-Identified Individuals

Sharp Edge Eye Syndrome (SEES) is a condition in which the sufferer experiences ocular pain or discomfort when viewing or mentally picturing a sharp object or edge. Although we were unable to identify any published reports of this condition, an internet search for “Sharp Edge Eye Syndrome” or “Visual Looming Syndrome” (used interchangeably) reveals several blog posts and internet forums discussing the condition (1–4). Posts report that SEES may make it difficult to fall asleep, drive, or use a computer. SEES patients have often consulted health care professionals without satisfaction (1).

Case Report:

MSR (primary author) is a healthy 28-year-old man who has experienced discomfort associated with viewing sharp objects for as long as he can remember. The earliest instance occurred as a child, while watching the movie, Matilda. His eyes became extremely uncomfortable when Matilda was placed in a spiked Iron Maiden. He describes his pain as a “sinus ache” and deep “discomfort,” as if “the object is actually poking my eye, slowly.” There is both a physical component of head or eye discomfort and a psychological discomfort. He feels the strong urge to look away, hold his hands to his eyes, and engage in mental distraction. The severity ranges from mild to moderate, with varying degree of severity. The severity has not changed over time, although symptoms once resolved for three months. Triggers include table corners, cutlery, writing implements, display hooks, branches and spears (Supplemental Figure S1), among many others. Objects pointed towards his eyes centrally or peripherally induce symptoms, but thinking about these objects can also cause discomfort. He denies a fear or phobia of these objects. Once triggered, an episode may range from seconds to hours. Exacerbating factors include fatigue and stress. Alleviating factors include placing blunting objects over triggers, sleeping with a soft cloth or eye mask with moderate pressure, squinting, pressing his fingers firmly on his eyelids, and distracting thoughts. He denies any disability stemming from this condition.

MSR’s younger brother suffers from similar symptoms. MRS denies a family history of eye disease except refractive error. His father has a history of migraines. MSR has attention deficit hyperactivity disorder (ADHD) but no other medical conditions. His ophthalmic examination is normal, including 20/15 uncorrected visual acuity in each eye, external, anterior segment, fundus exams, and intraocular pressure. Non-contrasted MRI was normal.

This study aims to explore the features of SEES, propose a definition of SEES, better understand its associated features and co-morbidities, and begin to determine its effect of vision-related quality of life (VRQOL).

Methods

Selection of study subjects

A cross-sectional web-based survey was made available on social media pages dedicated to SEES. The survey was made available to persons 18 years or older who experience eye pain or discomfort when viewing or imagining sharp objects (2–4). The study protocol was approved by the University of Utah Institutional Review Board (UofU IRB). The study followed the tenets of the Declaration of Helsinki, and informed consent was obtained from participants prior to their completion of the study instruments. The study was available from July 9–21, 2020.

Survey instrument

The survey instrument may be viewed in Supplemental Figure S1. It begins with two screening questions, asking whether viewing or thinking of sharp objects causes discomfort. Participants had to answer in the affirmative to one of these two questions in order to continue.

Demographics collected included age, gender, race, and geographic location. The survey included 22 de novo questions developed by the research team. These were created from descriptions from online forums dedicated to SEES, and from the first author’s experiences (1,2).

Additional questions explored whether this condition may be related to other conditions such as Alice in Wonderland syndrome (5), visual snow syndrome (6), stripe-induced visual discomfort (7), aichmophobia (needle phobia) (8), or synesthesia (9). A focus group of four individuals with self-identified SEES helped refine the questions. These individuals were excluded from the study.

The three-item ID-Migraine™ questionnaire (10) was included twice in the survey: First, the survey asked if SEES symptoms were accompanied by migraines or headaches. If a respondent self-reported that their symptoms were accompanied by migraine, or by headache scoring two or three on the ID-Migraine™ questionnaire, we concluded their symptoms were likely accompanied by migraine, and reported the sum of these individuals. Later in the survey, we asked if individuals experienced migraines independent of SEES symptoms. Likewise, we reported the number of subjects who experience migraine independent of symptoms as the sum of the individuals who self-reported migraine and the individuals who self-reported headache and scored two or three on the ID-Migraine™ questionnaire.

We used the 25-item National Eye Institute Visual Function Questionnaire (11) (NEI-VFQ-25). Items that used the phrase “because of your eyesight” were reworded to “because of your eye discomfort with sharp objects.” This change was based upon similar changes made by researchers adapting the NEI-VFQ-25 to blepharospasm (12). We used the General Anxiety Disorder-2 (13) (GAD-2), and the Personal Health Questionnaire Scale-2 (14) (PHQ-2). We categorized participants as having moderate to severe anxiety if they had a GAD-2 score of ≥ 3 or if they self-identified as having anxiety. We categorized participants as having moderate to severe depression if they had a PHQ-2 score of ≥ 3 or if they self-identified as having depression.

Statistical analyses

Data were tabulated (Excel 2020 for Windows) and R version 3.6.2 was used for data analyses (15). Data are presented as a fraction of the respondents who chose to answer the question.

Results

Between July 9–21, 2020, 77 participants completed the survey. Although the consent form and survey invitation stated that the survey was for individuals 18 years of age or older, four participants were under 18. We included these responses after further review by and approval from the UofU IRB. Although not every participant answered every question, every question in the survey was answered by at least 73 of the 77 respondents.

Demographics

The mean age was 29 years. Survey responses came from 17 different countries. The majority of participants identified as White / Caucasian. Results are summarized in Table 1.

Table 1. Demographics and Disease Characteristics of Survey Respondents.

Percentages are expressed as a fraction of the number of participants who responded to the question.

Age, mean (years)	29
Age at symptom onset, mean (years)	10
Female:male:nonbinary within group	32:43:1
Region of origin, n (%)
Europe	20 (26)
North America	44 (58)
Central and South America	4 (5)
Central Asia and Middle East	3 (4)
Southeast Asia	1 (1.3)
Oceania	3 (4)
Africa	1 (1.3)
Race*, n (%)
American Indian / Alaska Native	1 (1)
Asian	5 (7)
Black / African American	3 (4)
Hispanic / Latino	9 (12)
Native Hawaiian or Pacific Islander	1 (1)
Middle Eastern / North African	3 (3.9)
White / Caucasian	62 (82)
Prefer not to say	1 (1)

^*Participants had the option of selecting more than one race.

Site of Pain and Discomfort

84% reported discomfort or pain in both eyes, 49% reported discomfort located in between the eyes, and 42% reported discomfort in the front of the head.

Age of Onset

92% reported symptom onset before the age of 18 years (mean 10 years).

Triggering Objects

Although discomfort is triggered by viewing sharp objects or edges, 78% of respondents indicated that visualizing a triggering object could induce pain or discomfort. 58% reported that viewing a triggering object on a screen could induce symptoms. Table 2 includes a list of triggering objects.

Table 2.

Objects that may trigger discomfort. Common objects that may trigger symptoms, reported as a percent of respondents

Furniture (table, nightstand) corners	78
Pencils/pens	68
Knives	62
Needles	61
Open cabinet door corners	60
Forks	53
Department store display hooks	52
Scissors	52
Straws	38
Laptop corners	36
Tree branches	34
Umbrellas	27
Windshield wipers	27
Computer cursor	12
Other	26

When triggered, 82% of participants described the discomfort as feeling like a needle was being held up to their eyes and slowly moved forward, creating an urgent desire to look away. 57% indicated that it may feel like the object was physically poking their eyes. When a sharp object was pointed toward them, 78% reported needing to look away and 79% reported that the discomfort might continue after closing their eyes. 38% of participants were unable to sleep without covering their eyes. Despite these symptoms, when directly asked, “Would you say you have an unreasonable or excessive fear of sharp objects?”, 72% of respondents indicated they did not.

Accompanying Symptoms

Seven participants indicated that they experienced migraine when triggered. An additional 23 participants indicated they experienced headaches when triggered. Five of these 23 participants scored ≥ 2 on the ID-Migraine questionnaire. These 12 participants (16%) were categorized as having accompanying migraine (Table 3). Thirty-six percent of participants reported light sensitivity.

Table 3. Accompanying symptoms, co-morbid conditions, and family history.

Survey respondents were asked if their SEES symptoms were associated with migraines, headaches, and light sensitivity. Respondents were also asked if they had migraines or headaches independent of SEES symptoms. Respondents were asked about mental health conditions, other disturbances of visual perception, and a family history of migraine or SEES. Percentages are expressed as a fraction of the number of participants who responded to the question.

Accompanying symptoms, n(%)
Migraine (ID-Migraine + self-reported)	12 (16)
Headache	23 (30)
Light sensitivity	26 (36)
Co-morbid conditions, n(%)
Anxiety (GAD-2 + self-reported)	43 (58)
Depression (PHQ-2 + self-reported)	42 (57)
Migraines (ID migraine + self-reported)	19 (26)
Headaches	14 (19)
Alice in Wonderland syndrome	21 (28)
Visual snow	21 (27)
Obsessive-compulsive disorder	17 (23)
Attention deficit hyperactivity disorder	14 (19)
Restless leg syndrome	9 (12)
Stripe-induced visual discomfort	8 (10)
Synesthesia	6 (8)
Family history, n(%)
Family history of migraines	32 (42)
Family history of SEES	15 (20)

Duration of Discomfort

When asked how long the discomfort lasted, 34% indicated “seconds,” 53% “minutes,” and 12% “hours.” When asked the longest time of freedom from symptoms, 16% indicated “hours,” 40% “days,” 36% “months,” and 9% “years.” In the last year, 29% experienced worsening, 14% improvement, and 57% no change of symptoms.

Exacerbating and Alleviating Factors

Participants found their discomfort to be worse when tired (70%), when stressed (57%), when the object was viewed in bright light (35%), or when the object was shiny (21%). Participants reported that their pain could be improved if they looked away from the trigger (79%), put pressure on both eyes (69%), covered the trigger with something soft (53%), or thought of something else in an effort to ignore the sharp object (43%). They reported they could improve their pain by covering one eye (29%), being well-rested (26%), applying pressure to the temples (20%), wearing glasses or sunglasses (17%), or wearing a hat (5%). Some respondents reported sleeping with an eye mask (12%) or with a soft cloth over the eyes (17%) to improve their discomfort.

Co-morbid Conditions

Anxiety, depression and other mental health conditions.

Table 3 shows a significant number of respondents reporting moderate to severe anxiety, moderate to severe depression, obsessive- compulsive disorder (OCD), and ADHD.

Migraine.

Thirteen participants indicated that they experienced migraines independent of SEES symptoms. 14 participants indicated they experienced headaches independent of SEES, of whom 6 scored ≥ 2 on the ID migraine questionnaire. These 19 (26%) participants were categorized as having migraine in Table 3.

Other disturbances of visual perception.

Participants reporting Alice in Wonderland syndrome, visual snow, stripe-induced discomfort, and synesthesia are documented in Table 3.

Family History of SEES and Migraine

Twenty percent of our respondents reported at least one biologically related family member with SEES, and almost half of participants were aware of a family history of migraine.

Seeking Medical Attention for SEES

Twenty-six percent of participants reported that they had consulted a medical professional about their pain syndrome. Most expressed feeling frustrated by these medical encounters when no diagnosis or treatment was rendered. Many participants reported feeling that the medical consultant dismissed their symptoms. Others reported that they were referred to other specialists. Some people with SEES, having researched their condition on the internet, found many comments describing the futility of a medical consultation, and for this reason did not seek medical attention.

Vision-Related Quality of Life

Seventy-six of the 77 participants completed the NEI-VFQ-25, and their responses are tabulated in Table 4. The mean composite score as well the sub-scores for general health, general vision, ocular pain, driving, and mental health were all below 80.

Table 4.

Vision-related quality of life assessed in survey participants with SEES using the 25-Item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25).

Participants completing the NEI-VFQ-25, n	76
NEI-VFQ-25 composite score, mean	78
NEI-VFQ-25 subscale score, means
General health	61
General vision	73
Ocular pain	68
Near activities	82
Distance activities	88
Driving	79
Color vision	97
Peripheral vision	85
Vision-specific
Social functioning	90
Mental health	61
Role difficulties	72
Dependency	89

Conclusions

Proposed Diagnostic Criteria

Based on the syndrome characteristics that at least two-thirds of the respondents reported, we propose the following diagnostic criteria for SEES:

1. Ocular pain or discomfort when viewing sharp objects or edges.

2. Presence of at least two of the following:

   1. Thinking of sharp objects causes pain or discomfort.
   2. Triggered pain or discomfort involves both eyes.
   3. Viewing sharp objects causes a sensation as if a needle is pointed at the eye(s) and is moving toward them.
   4. Discomfort continues even after closing one’s eyes.
   5. Discomfort improves when looking away from the object.
3. Triggers:

   1. Sharp edges or corners.
   2. Sharp or pointed objects.
4. Exacerbating and Alleviating Factors:

   1. Symptoms are worse when tired or stressed.
   2. Symptoms are improved by placing pressure over the eyes.

5. Age of onset before age 18 years.

6. Symptoms are not better explained by another disease, disorder or syndrome.

Mental Health and other Visual Perceptual Conditions

A significant proportion of our respondents appear to have anxiety, depression, OCD, and/or ADHD. By comparison, the worldwide prevalence of anxiety is estimated to be 7.8% (16) and the prevalence of depression is estimated to be 3.4% (17). The prevalence of OCD and ADHD are estimated to be 2.1% (18) and 5.3% (19), respectively. Our respondents reported features of other syndromes affecting visual perception, suggesting that this group of individuals may be prone to perturbation of visual perception and that these disturbances of visual perception may share some common etiology. The role of psychoactive or other drugs was not considered for this study given the community reported young age of onset.

Vision-Related Quality of Life

Our data suggest that persons who identify as having SEES experience a significant reduction in VRQOL. Reference data from a sample of the German general population demonstrated scores >90 (20), but the mean composite score for our respondents on the NEI-VFQ-25 was 78. This mean may be compared to those reported for migraine (85) (21), multiple sclerosis with a history of optic neuritis (85) (22), idiopathic intracranial hypertension (82.4) (23), neuro- ophthalmic disorders other than multiple sclerosis (81) (24), hemifacial spasm (80) (12), and dry eye (80) (25). This observation indicates that SEES is not just a disturbance of visual perception, but a health condition that results in a significant reduction in VRQOL.

Ocular Pain Induced by a Visual Image

We have previously reported that the most common ocular causes of eye pain in a tertiary eye clinic are inflammatory ocular conditions (26) and the most common neurologic cause of eye pain in a tertiary neurology clinic was migraine. While 16% of our participants had migraine in conjunction with SEES symptoms, and 26% had migraine separate from SEES events (with only 3 people experiencing both SEES and Non-SEES related migraine), migraine was by no means a universal symptom, and therefore not the sole explanation for SEES symptoms. Inflammatory eye conditions and migraine both involve activation of the trigeminal pathway (27). SEES may be unique because the sensation of pain appears to originate in the visual cortex, where the triggering object is recognized. Previous research has demonstrated that photographs of the sun can cause pupillary constriction (28), suggesting that neural pathways beginning in the visual cortex may project to subcortical brain areas. While phenomena of visually induced sensations such as stripe-induced discomfort and synesthesia have been investigated, this study is the first to report a condition in which a visual construct (present or mentally produced) may produce pain.

MRI and EEG are important diagnostic tools and multiple patients have anecdotally reported normal imaging following workup with their individual providers. MSR had a normal MRI. Because participants were not administered MRI or EEGs as a part of this study, we cannot rule out seizure disorders or structural disease at this time. Future imaging studies of patients with SEES may help us to better understand what neural pathways are activated by looking at or thinking about sharp objects.

Limitations

We used a convenience sample and the survey was open for 12 days. For these reasons we cannot generalize our results to all persons who may have SEES. Furthermore, the associations we documented only represent a single time point.

Conclusions

The unique symptoms reported by our respondents lead us to conclude that SEES represents a distinct visual phenomenon. Our survey indicates that a significant number of SEES patients also suffer from mental health conditions and that a significant proportion suffer from migraines, light sensitivity, and other disturbances of visual perception. Although the pathophysiology of SEES is unknown, 20% of respondents reported a family history, suggesting a possible genetic predisposition. Patients with SEES appear to have substantially reduced VRQOL.

Although there are no known treatments for SEES, physicians caring for these patients could suggest using some of the alleviating aids employed by the survey respondents. Reassuring the patient that there are others with these symptoms and that they do not appear to be associated with any serious ophthalmic or neurologic condition may help relieve distress associated with SEES. Recognizing the association between SEES and mental health conditions can lead to increased screening for mental health conditions, which may also help decrease distress associated with SEES. Further study, perhaps with functional MRI or connectome may help us better understand the pathophysiology of SEES and develop effective treatments for SEES patients.