Retinal lattice degeneration is a common eye condition where the outer edge of the retina becomes thinner and more fragile. Many people with retinal lattice degeneration have no symptoms, but some notice flashes, new floaters, or blurred vision if a tear or detachment develops. It usually lasts long term and is often found in teens or adults during a routine eye exam, especially in people who are nearsighted. Not everyone will have the same experience, and early symptoms of retinal lattice degeneration may be absent until a complication happens. Retinal lattice degeneration is not life-threatening, and treatment is often not needed unless there is a retinal tear, bleeding, or a high risk of detachment, when laser treatment or freezing treatment may be used.
How many people live with Retinal lattice degeneration?
Retinal lattice degeneration is usually estimated to affect about 6% to 8% of people, and the range varies because it depends on how carefully eye exams look for it; using 2024 population totals, that suggests roughly 490 to 660 million people worldwide (Byer, 1989; United Nations, 2024). Using the same estimate, about 20 to 27 million people in the United States may be living with it (Byer, 1989; U.S. Census Bureau, 2024).
Overview
Retinal lattice degenerationSymptoms
Retinal lattice degeneration often causes no symptoms and is usually found during a routine eye exam. If it leads to a retinal tear, you may notice new floaters, flashing lights, blurred vision, or a shadow in your side vision.
Outlook and prognosis
Most people with retinal lattice degeneration keep stable vision and never develop serious problems. The main concern is a small lifelong risk of retinal tears or detachment, so regular eye exams and urgent care for new flashes, floaters, or a curtain-like shadow matter.
Causes and risk factors
Retinal lattice degeneration has no single known cause. Risk is higher with nearsightedness, a family history, and certain inherited connective tissue conditions; eye aging may contribute, and retinal tears or injury can raise the chance of related problems.
Genetic influences
Genetics can matter in retinal lattice degeneration, but it is usually not caused by a single gene change. Risk may be higher in families and in people with inherited conditions linked to strong nearsightedness or weaker connective tissue.
Diagnosis
Retinal lattice degeneration is usually diagnosed during a dilated eye exam, when an eye doctor looks closely at the retina. They may use special lenses, retinal imaging, or both to confirm the diagnosis of retinal lattice degeneration.
Treatment and drugs
Retinal lattice degeneration is usually managed with regular dilated eye exams to watch for tears or early retinal detachment. If weak spots start to tear, laser treatment or freezing therapy can help seal them. Most people do not need daily medicines.
Symptoms
Retinal lattice degeneration often causes no day-to-day problems, so many people only learn they have it during a routine dilated eye exam. When symptoms do happen, they are usually linked to pulling on the retina or to a retinal tear, rather than the lattice areas themselves. Symptoms vary from person to person and can change over time.
Many people with retinal lattice degeneration notice nothing at all. In fact, there may be no early symptoms of retinal lattice degeneration until an eye doctor sees it on an exam.
Brief flickers or flashes, especially off to the side of your vision, can happen if the vitreous gel tugs on the retina. Some people notice this more in dim rooms or when moving their eyes quickly.
Floaters can look like specks, threads, or cobweb-like shapes drifting across your sight. A sudden increase in floaters can be a warning sign of a retinal tear and should be checked promptly.
Vision may become blurry or less sharp if a retinal tear or detachment starts to affect the eye. This is not the most common first symptom, but it matters when it appears.
How people usually first notice Retinal lattice degeneration?
Retinal lattice degeneration is often first noticed in a surprisingly quiet way: many people have no symptoms at all, and it is found during a routine dilated eye exam when an eye doctor sees thin, stretched areas in the retina. When symptoms do show up, the first signs of retinal lattice degeneration are usually new floaters, brief flashes of light, or a sense that something has changed in the edge of your vision. These symptoms do not always mean an emergency, but because lattice degeneration can sometimes lead to a retinal tear or detachment, sudden flashes, a burst of floaters, or a shadow like a curtain over part of your vision should be checked right away.
Types of Retinal lattice degeneration
No distinct types of retinal lattice degeneration are widely recognized.
Can I slow down the onset of symptoms?
No—there is no good evidence that lifestyle changes or medicines can meaningfully delay the start of symptoms from retinal lattice degeneration, a thinning in the retina that often causes no symptoms unless a tear or detachment develops. Healthy habits are still good for overall eye health, but research has not shown that diet, exercise, sleep, or supplements can prevent lattice degeneration or stop it from becoming noticeable; lowering general eye risk is not the same as preventing this condition. What can help is regular dilated eye exams if you are at higher risk and urgent care for new flashes, floaters, or a curtain-like shadow, because doctors can sometimes treat a retinal tear early and lower the chance of a more serious problem, even though this cannot guarantee symptoms will never happen.
What genetics can tell you about symptoms
For most people with retinal lattice degeneration, genetics cannot clearly predict which symptoms they will have, how severe the condition will be, or exactly when problems might start. Lattice degeneration can run in families and is more common in people who are very nearsighted, which suggests inherited factors play some part, but it is usually not tied to one single gene change in the way some rare inherited eye disorders are. In day-to-day care, genetics is less useful than regular eye exams for spotting changes such as retinal tears or a higher risk of retinal detachment.
Causes and risk factors
When people ask about the causes of retinal lattice degeneration, there is rarely one clear trigger. It is more common in people who are very nearsighted, and it can run in families. Some inherited conditions that affect the eye or the body's connective tissues can also raise the risk. Lifestyle is not a major direct cause, but eye injury and activities with a higher chance of trauma can make retinal tears or detachment more likely. Not everyone with the same risk develops the condition, so regular eye exams matter if you have risk factors for retinal lattice degeneration.
What are the most common causes or risk factors?
The exact cause of retinal lattice degeneration is not fully known, but it often seems to be linked to how the eye is built and can run in families. It is much more common in people who are very nearsighted, and the risk is also higher if a close family member has had it or if the other eye has had a retinal tear or a retinal detachment, when the light-sensitive lining at the back of the eye pulls away. Less often, it can be seen in people with inherited conditions that affect the body’s support tissues, such as some disorders that also affect the eyes and joints.
Environmental and biological risk factors
Retinal lattice degeneration is usually linked to how the eye is built, especially at the far edges of the retina. Doctors often group risks into internal (biological) and external (environmental). For people looking up risk factors for retinal lattice degeneration, most established ones are internal, and clear outside causes are limited.
People with moderate or high nearsightedness are more likely to have retinal lattice degeneration. When the eye is longer from front to back, the outer retina can be stretched and thinner.
Some eyes have natural weak spots in the peripheral retina or firmer attachment between the retina and the clear gel inside the eye. These body-based differences can make lattice-like thinning more likely.
Retinal lattice degeneration can be found at many ages, but age-related changes in the eye’s gel can make thin retinal areas more noticeable and more clinically important. This helps explain why it may be discovered later, even if it began earlier.
A significant blow to the eye can stress the outer retina and may reveal weak areas that were not known before. It is not thought to be a common main cause, but it can matter more in eyes that are already vulnerable.
Genetic risk factors
For many living with retinal lattice degeneration, the reason it appears is not fully clear. The main genetic risk factors for retinal lattice degeneration are family history, inherited high myopia, and a few uncommon inherited disorders that affect the eye’s supporting tissues. Some risk factors are inherited through our genes. In most cases, doctors cannot point to one single gene as the cause.
Family history: Having close relatives with retinal lattice degeneration can raise the chance of having it too. This points to an inherited tendency, even though most families do not have one clearly identified gene change. People with the same risk factor can have very different experiences.
Inherited high myopia: People who inherit strong nearsightedness, especially high myopia, are more likely to develop retinal lattice degeneration. When the eye is longer than usual, the retina can be stretched more, which may make thin areas easier to form. Many have no early symptoms of retinal lattice degeneration, so it is often found during a dilated eye exam.
Stickler syndrome: This inherited condition affects collagen, a protein that helps support the eye, and it is strongly linked to lattice changes in the retina. Many living with Stickler syndrome also have a higher risk of retinal tears or retinal detachment.
Wagner syndrome: This rare inherited eye disorder changes the clear gel inside the eye and can be linked with retinal lattice degeneration or similar peripheral retinal thinning. Because it runs in families, doctors may think about it when several relatives have related retinal problems.
Marfan syndrome: People with Marfan syndrome can be more likely to have thinning in the outer parts of the retina, including lattice degeneration. The same inherited connective tissue weakness that affects other parts of the body can also affect eye tissues.
Lifestyle risk factors
For retinal lattice degeneration, there are no strong, proven lifestyle causes in the way there are for many metabolic or cardiovascular diseases. Still, how lifestyle affects retinal lattice degeneration can matter because some habits may raise the chance of retinal tears, delay detection of warning symptoms, or worsen outcomes if a detachment develops. The most useful discussion of lifestyle risk factors for retinal lattice degeneration focuses on eye safety, symptom response, and habits that support retinal care.
Activities with a higher risk of blows to the head or eye can increase the chance that fragile retinal areas develop a tear. Using appropriate protective eyewear during racquet sports, contact sports, or hazardous work may lower that risk.
Sudden jolting or forceful movement is not a proven cause of lattice degeneration, but intense activities may be more concerning if a retina is already vulnerable. People who notice new flashes, floaters, or a curtain-like shadow after exertion should seek urgent eye care.
Skipping dilated retinal exams can allow tears or early detachment to go unnoticed until vision is threatened. Regular follow-up is especially important if lattice degeneration has already been found or if new visual symptoms appear.
Waiting on new flashes, a burst of floaters, blurred side vision, or a shadow in the vision can delay treatment of a retinal tear or detachment. Fast evaluation can make vision-saving treatment more likely.
Risk prevention
Many people with retinal lattice degeneration feel completely fine day to day, so prevention is mostly about protecting vision and lowering the chance of a retinal tear or retinal detachment. There is no proven way to fully prevent retinal lattice degeneration itself, but careful eye care can reduce complications and help problems get treated early. Prevention is about lowering risk, not eliminating it completely. This matters most if you are very nearsighted, have had an eye injury, or have a family history of retinal detachment.
Regular dilated eye exams are one of the best ways to monitor retinal lattice degeneration before it causes trouble. An eye specialist can look for weak spots, small tears, or other changes that may need closer follow-up.
Learn the early symptoms of retinal detachment, such as a sudden shower of floaters, new flashing lights, or a dark curtain in your side vision. If these happen, get urgent eye care the same day because fast treatment can help protect sight.
Wearing protective eyewear during sports, yard work, or jobs with flying debris can lower the chance of an eye injury that could trigger a tear. This is especially important for people with retinal lattice degeneration or high myopia.
If you are very nearsighted, keep up with routine eye visits because high myopia raises the risk linked to retinal lattice degeneration. Let your eye doctor know about any change in blur, flashes, or floaters rather than waiting to see if it passes.
Can you prevent Retinal lattice degeneration?
There is no proven way to prevent retinal lattice degeneration, because it usually happens due to the way the back of the eye develops rather than something you can control. If you are very nearsighted or have a family history, regular dilated eye exams can help find changes early and lower the chance that a tear or retinal detachment is missed, but they do not stop lattice degeneration from forming. Protecting your eyes from injury is still a good idea, although it has not been shown to prevent this condition itself.
Transmission
Retinal lattice degeneration is not infectious, so it cannot be caught from someone else through touch, the air, sex, blood, or everyday contact. For many living with Retinal lattice degeneration, the question is not contagion but how Retinal lattice degeneration is inherited.
This eye change can run in families, and it is more common in people who are very nearsighted, which suggests that inherited traits may play a role. Even so, Retinal lattice degeneration usually does not follow a simple, predictable parent-to-child pattern, and many people with it do not know of anyone else in the family who has had it.
When to test your genes
For retinal lattice degeneration, genetic testing is not usually needed because this condition is most often diagnosed with a dilated eye exam, not a DNA test. Testing may be worth discussing if you or close relatives have repeated retinal detachments, very early severe nearsightedness, or signs of an inherited syndrome such as Stickler syndrome.
Diagnosis
Retinal lattice degeneration is usually found during an eye exam, often before it causes symptoms. Some people learn about it after new flashes, floaters, or a tear in the retina prompts a closer look. Doctors usually begin with a dilated eye exam, and the diagnosis of retinal lattice degeneration is mainly based on what the eye doctor can see in the far edges of the retina.
Eye drops are used to widen the pupils so the doctor can carefully examine the peripheral retina. This is the main test for finding the thin, crisscrossed areas that suggest retinal lattice degeneration.
The doctor will ask about flashes, floaters, blurred vision, or a shadow in your side vision. These symptoms can help show whether lattice degeneration is quiet or linked to a retinal tear or detachment.
Special photos or widefield imaging may be used to document the retina and track changes over time. Images can be helpful, but they do not replace a careful dilated exam.
The eye doctor may use a bright light and handheld lens, and sometimes gentle pressure on the eyelid, to see the outer retina more clearly. This helps detect small holes, tears, or areas pulling on the retina.
How is Retinal lattice degeneration diagnosed?
Retinal lattice degeneration is usually diagnosed during a dilated eye exam, when an eye doctor uses drops to widen the pupils and then looks closely at the retina, the light-sensing layer at the back of the eye, for the thin, patchy areas and small holes that are typical of this condition. Sometimes the doctor also takes retinal photos or uses other eye scans to keep track of changes or to check for a tear or a retinal detachment, but the diagnosis is mainly based on the eye exam itself.
Stages of Retinal lattice degeneration
Retinal lattice degeneration does not have defined progression stages. This is because it is usually a structural change in the far edge of the retina rather than a condition that moves through clear step-by-step phases over time. Often the process begins when you notice changes in daily life, but early symptoms of retinal lattice degeneration are often absent and many people only learn they have it during a routine dilated eye exam. Eye doctors usually monitor retinal lattice degeneration with regular retinal checks and may look more closely if there are flashes, new floaters, or signs of a retinal tear or detachment.
Outlook and prognosis
The outlook for retinal lattice degeneration is generally good, and many people never develop symptoms or vision loss. The main long-term concern is a higher risk of retinal tears or rhegmatogenous retinal detachment, especially in people who are very nearsighted, have had eye trauma, or have a family history of retinal detachment. Most cases remain stable over time with regular dilated eye examinations, and preventive laser or cryotherapy may be used in selected high-risk situations. If a retinal tear or detachment occurs, prognosis depends on how quickly it is treated, with earlier repair offering a better chance of preserving vision. Retinal lattice degeneration itself is not life-threatening and does not affect overall mortality. Patients should seek urgent eye care for new flashes, a sudden increase in floaters, or a curtain-like shadow in their vision, because these can signal a sight-threatening complication.
Long-term effects
Retinal lattice degeneration often has little day-to-day impact, and many people live with it for years without noticing any change in vision. Long-term effects vary widely, but the main concern is that the thin areas of retina can be more prone to tears over time. For many, the condition stays stable, while a smaller group develop complications that can threaten sight if they are not treated promptly.
Many people with retinal lattice degeneration never develop serious vision problems, and the thin retinal areas remain unchanged for years. In these cases, long-term outlook is generally good.
As the gel inside the eye changes with age, it can pull on weak retinal areas and cause flashes or new floaters. These can be among the early symptoms of retinal lattice degeneration when a tear is starting or traction is increasing.
The most important long-term effect is a higher chance of a retinal tear forming in the weakened area. A tear may not hurt, but it can create a pathway for fluid to slip under the retina.
If fluid passes through a tear, the retina can lift away from the back of the eye, which is called a retinal detachment. This can cause a curtain-like shadow, blurred vision, and lasting vision loss if not treated quickly.
How is it to live with Retinal lattice degeneration?
For many people, living with retinal lattice degeneration does not change everyday life very much, because it often causes no symptoms and is found during a routine eye exam. The main impact is staying alert for warning signs of a retinal tear or detachment, such as new flashes of light, a sudden increase in floaters, or a shadow coming across your vision, and keeping up with regular dilated eye checks. For family members and others around you, the effect is usually small, but it can help if they know those urgent symptoms too, since quick treatment can protect sight.
Treatment and drugs
Retinal lattice degeneration often does not need active treatment if it is not causing problems, and many people are simply monitored with regular dilated eye exams to watch for retinal tears or early signs of detachment. If retinal lattice degeneration leads to a tear, or if your eye doctor thinks a tear is likely, treatment is usually done with a laser or a freezing procedure to seal the weak area and help lower the chance of the retina pulling away. There is no specific medicine or eye drop that repairs retinal lattice degeneration itself, although treatment may also include managing related eye conditions when present. Not every treatment works the same way for every person, so the plan depends on your symptoms, whether one or both eyes are affected, and your overall risk of retinal detachment.
Can you cure Retinal lattice degeneration?
No, retinal lattice degeneration cannot be cured or reversed. In many people it does not need treatment, but regular eye exams are important because if a weak area causes a tear or hole in the retina, treatment such as laser or a freezing treatment can help lower the chance of the retina pulling away.
Non-drug treatment
For many living with retinal lattice degeneration, the main non-drug approach is careful monitoring rather than active therapy. There is no exercise, vitamin plan, or home treatment proven to repair the thin areas in the retina or prevent all complications. Non-drug treatments often lay the foundation for catching retinal tears early, when fast care matters most. Some may find that knowing the warning signs and protecting the eyes in daily life helps them feel more prepared.
Regular dilated eye exams are the most important non-drug step for retinal lattice degeneration. They help an eye specialist watch for changes, especially if you are very nearsighted or have had problems in the other eye.
Learning the early symptoms of retinal lattice degeneration complications can help you act quickly. New flashes, a sudden shower of floaters, or a shadow like a curtain over part of your vision need urgent eye care.
Protecting your eyes from injury can lower the chance of trauma that might trigger a retinal tear in a vulnerable retina. Safety glasses are worth using for sports, yard work, tools, or any activity with a risk of impact.
Most people with retinal lattice degeneration can stay active, but some may be advised to avoid activities with a high risk of direct eye trauma. Not every approach works the same way, so activity advice should match your eye history and overall risk.
Your genes may have an impact on how drugs work for you
For people with retinal lattice degeneration, genes do not usually have a known, direct effect on how the condition is treated, because care is mostly based on eye exams and, when needed, procedures like sealing weak areas of the retina rather than long-term medicine. In other words, there are no well-established examples where a common medicine for this condition is chosen or dosed based on someone’s genes. If a person also has another eye condition that needs medication, or a family history of inherited eye disease, their doctor may think more broadly about genetics, but this is not a routine part of care for retinal lattice degeneration itself.
Pharmacological treatments
For retinal lattice degeneration, there is no medicine that repairs or reverses the thinned areas of the retina. In most people, treatment for retinal lattice degeneration is careful monitoring rather than daily or long-term drugs. Medicines may still be used around eye procedures or if a retinal tear or detachment develops, but they treat the complication or support recovery, not the lattice changes themselves.
There is no standard pill, injection, or eye drop that directly treats retinal lattice degeneration. Many people with retinal lattice degeneration do not need medication unless a related problem, such as a retinal tear, is found.
Proparacaine or tetracaine eye drops may be used to numb the eye before laser treatment or cryotherapy. These medicines improve comfort during the procedure, but they do not change the underlying lattice degeneration.
Prednisolone acetate eye drops may be prescribed for a short time after a retinal procedure to calm inflammation. This is supportive care after treatment, not a medicine that prevents lattice areas from progressing.
Ketorolac eye drops are sometimes used after eye procedures to reduce soreness and irritation. Some medicines work quickly, while others are mainly there to support healing over a few days.
Genetic influences
Retinal lattice degeneration can sometimes appear in more than one family member, especially in families with strong nearsightedness or certain inherited disorders that affect the eye. It’s natural to ask whether family history plays a role. The genetic causes of retinal lattice degeneration are not fully understood, and for most people there is no single gene that explains why it happens. Instead, doctors think inherited traits may influence how the retina and the gel inside the eye develop, which can make lattice changes more likely in some families. Rare inherited conditions such as Stickler syndrome or Wagner syndrome can increase the chance of retinal lattice degeneration because they affect the eye’s support tissues. Still, a family connection does not mean retinal lattice degeneration is certain, and this history mainly helps eye doctors decide who may benefit from closer retinal monitoring.
Is Retinal lattice degeneration genetic?
Genetics can matter in retinal lattice degeneration, but it is usually not caused by a single gene change. Risk may be higher in families and in people with inherited conditions linked to strong nearsightedness or weaker connective tissue.
Having a genetic risk is not necessarily a diagnosis
Genetic variants, meaning differences in genes, are a normal part of human biology and are common across the general population. Most of these variants do not have a direct effect on health and are simply part of the natural diversity seen in people. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. In some cases, though, a single well-understood variant in a certain gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For most people with retinal lattice degeneration, genetics do not usually decide which treatment or medicine they receive, because this condition is most often managed with regular eye exams and, when needed, preventive laser treatment rather than long-term drugs. Treatment choices depend more on what the eye doctor sees, such as small retinal tears, bleeding, new flashes or floaters, and the overall risk of retinal detachment. Not every difference in response is genetic, but family history can matter: if retinal lattice degeneration occurs as part of an inherited eye or connective tissue condition, doctors may recommend closer follow-up and sometimes earlier treatment. At this time, genetic testing for retinal lattice degeneration is not routine when it appears on its own, and there are no standard gene-based tests used to choose medicines specifically for it. Most medicines used around eye procedures are selected based on safety, allergies, age, and other health conditions rather than DNA results. If there is a strong family pattern of retinal detachment or signs of a broader inherited condition, a genetics specialist may help clarify risk and guide the follow-up plan.
Interactions with other conditions
For many people, retinal lattice degeneration causes no day-to-day problems, but it matters more when other eye conditions are present. Another important aspect is how it may link with other diseases. Retinal lattice degeneration is seen more often in people with significant nearsightedness, and together these can raise the chance of retinal tears or a detached retina. It can also occur alongside inherited connective tissue conditions such as Stickler syndrome or Marfan syndrome, where the retina may already be more fragile and eye checks often need to be more careful. If someone also has a posterior vitreous detachment, meaning the gel inside the eye pulls away with age, the weak areas from retinal lattice degeneration may be more likely to tear. Because of these overlaps, people living with retinal lattice degeneration should mention any family history of retinal detachment and ask about warning signs such as new flashes, floaters, or a curtain-like shadow over vision.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Retinal lattice degeneration?
Retinal lattice degeneration often causes no symptoms, so flashes, floaters, or a curtain-like shadow in vision are more often caused by the gel inside the eye pulling away with age, a retinal tear, or a retinal detachment. Migraine-related visual changes and bleeding inside the eye can also cause similar symptoms, which is why new flashes, a sudden shower of floaters, or any dark shadow over your vision should be checked quickly by an eye doctor.
History
For many living with retinal lattice degeneration, there are no day-to-day symptoms at all, and the condition is often found during a routine eye exam rather than because something feels wrong. When symptoms do happen, they are usually linked to complications, such as new flashes of light, a sudden increase in floaters, or changes in side vision. This can make the history of retinal lattice degeneration a little unusual: doctors first learned about it by carefully examining the back of the eye and connecting what they saw with the small number of people who later developed tears or retinal detachment.
As medical science evolved, ophthalmologists began to describe a characteristic pattern of thinning in the peripheral retina, the light-sensitive layer lining the back of the eye. Over time, these descriptions became more precise as eye examination tools improved, especially with better lenses and brighter, wider views of the retina. That helped doctors see that retinal lattice degeneration was not a rare curiosity, but a fairly common finding that many people may have without ever knowing it.
Later research showed that the condition could run in families and could appear alongside severe nearsightedness or other eye problems, although many people with retinal lattice degeneration have no major vision trouble from it. Not every early description was complete, yet together they helped build today’s approach: identify the pattern, watch for warning signs, and treat only when the risk of a tear or detachment is high enough to matter. This history also explains why modern eye care focuses so much on education about the early symptoms of retinal lattice degeneration, since prompt attention to sudden flashes, floaters, or a curtain-like shadow can help protect sight.