my dogs eye turned blue overnight

From there, treatment depends on the underlying cause of the injury. Thank you! Glaucoma 6. A free weekly newsletter with expert sports betting insight and analysis. It is also seen in both eyes typically and is non-painful. Most Pet Parents first notice their furry family members change in behavior, such as them bumping into things or not being able to see a treat that is in front of them. By acting quickly you just might save her vision and keep those beautiful eyes sparkling again. Vet now. Keep the fur around your dog's eyes trimmed short. Yes this absolutely warrants an immediate ER trip. This means it is a normal consequence of age. Reasons Your Dog's Eyes Turn Cloudy Suddenly 1. Prompt diagnosis is important. This condition usually does not lead to compromised vision. Injury to the eye, and bacterial infections can also cause inflammation as a secondary symptom to the initial cause. Ulcers are usually treated with medicated drops to prevent infection and relieve pain, and in severe cases may require surgery to save your dogs eye, so it is best to get your dog to the veterinarian as soon as you notice signs of ocular discomfort, like squinting or rubbing at the eye with a paw. Ulcers can form, and in severe cases lead to perforation of the eye itself. Once your dog is awake, your vet will likely prescribe medications. If a cataract develops, it can be surgically corrected, and this procedure should be pursued early in the course of the disease for best results. Your e-mail address will be used to confirm your account. Symptoms of Glaucoma include conjucntivits (red eye), discharge from the eye, light sensativity, possible swollen eye. Pigmentary keratitis refers to brownish-black discoloration of the eye's surface caused by the deposition of pigmented melanin granules. The treatment for your dogs cloudy eyes depends on the cause, the age of your dog, the progress of the problem, and your dogs discomfort. Cataracts progress through four stages of maturity: incipient, immature, mature, and hypermature. Lastly, heavy panting, or blue or pale gums or tongue indicate a serious issue. You may notice that your pet is squinting and the eye may produce excessive tears. This is an age-related change where the lens in each eye becomes less clear and cloudy. A dogs eyes are one of its most striking features. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain. We should state that the first reason your dog has blue eyes might not be a discoloration. The best course of action is to ensure their general well-being to give them the best chance at slowing the degeneration. However, always take your dog to the vet to be certain of which ailment he/she may be experiencing. If you want to read similar articles to My Dog Has Blue Eyes - Causes and Treatment, we recommend you visit our Other health problems category. As the condition worsens and pressure increases, the pupil can dilate and the cornea becomes cloudy. If your dog has an acute injury to the eye, such as bumping into a foreign object or getting bitten by another dog, it should be considered a medical emergency. Severe cases of dry eye can lead to corneal ulceration and scarring, which falls into the second category. There are two reasons a dog's eyes look blue: Cataracts or Nuclear Sclerosis. The changes to their eyes happen gradually and it is not painful. Making sure to keep the eye clean and dry, and preventing rubbing can also help reduce the chances of further injury and irritation, helping with healing. Chronic dry eye can also cause corneal ulceration. It has a clear outer protective barrier called the cornea and a white fleshy part called the sclera. Put tags or bells that jingle or make noise on other animals in the house and consider wearing one yourself so that your blind dog knows where his companion is. Vision does not appear to be significantly affected in dogs diagnosed with lenticular sclerosis. This condition can be uncomfortable, and Shetland Sheepdogs appear to be the most susceptible breed. Dr. Karie Johnson2020-02-06T16:02:24-06:00, Dr. Karie Johnson2020-02-06T16:03:35-06:00, Dr. Karie Johnson2020-05-01T09:54:07-05:00, 2020 VIP Vet Visit, Inc. | All Rights Reserved |. Do not give OP specific treatment instructions, including instructions on meds and dosages. If the dog's eye is turning blue unnaturally, then there are not many possible causes. There are three types of corneal dystrophy: Dogs who suffer from cataracts will typically develop a cloudy, whitish, or crackly appearance in their eye/s. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. NUCLEAR SCLEROSIS Nuclear sclerosis (also known as lenticular sclerosis) is a normal aging change of the lens within the eye. Her desire to strengthen the human-animal bond while providing enhanced preventative care led her to start VIP Vet Visit an at-home veterinary care option that provides less stress, more convenience and better care. Unlike nuclear sclerosis, cataracts in dogs cause vision impairment which can lead to total blindness if not managed properly. Blue eyes can be a sign of Infectious canine hepatitis which is a disease of the liver and other organs caused by the adenovirus type 1. This layer is not see-through and can completely block light from entering the eye leading to blindness. Cataracts develop as result of an increased amount of protein accumulated in the eye. The lens in both dog eyes and human eyes acts like a camera lens, focusing light on the film at the back of the eye, called the retina, where the brain then processes the information to form a picture of the world around it. This is due to fluid build-up and debris forming behind it. While glaucoma is relatively rare in dogs, there are some breeds more predisposed. You have questions, we have answers. These can cause minor problems or major ones. If you notice your dog has cloudy eyes, and is experiencing the symptoms of an emergency, it is best to seek out veterinary care from your vet or an emergency clinic right away. Simply click here to return to. Cloudy eyes can be a symptom of a variety of eye problems, and some can be painful for your dog. Eye color change in animals, especially when not due to age, is very serious. This is considered a normal change in the lens associated with aging, and is observed as a cloudiness or bluish discoloration on the pupil. In less severe cases, medications to help reduce swelling, remove fluid from the eye, and decrease eye pressure can help. Glaucoma is also something we see in animals. Some eye conditions are hereditary, so its good to be aware of those common to your dogs breed. A: I would have your veterinarian check her eyes to be sure of the diagnosis as soon as you can. No she went in for a regular check up. I cant see the black part in the middle anymore. There are many variations between these two extremes, but we always need to be careful of symptoms. Below, Ive outlined five common conditions that can cause blue or cloudy eyes whilesome are benign, others are very serious and can lead to total blindness. In the case of an eye that is severely damaged or infected, removal is generally the best course of action. There are two types of glaucoma: primary or inherited glaucoma, and secondary glaucoma, which is usually caused by another condition such as cataracts, a lens luxation or subluxation (where the lens shifts position in the eye), cancer, inflammation, or retinal detachment. Cataracts can appear in one or both eyes and it can progress at varying rates. Nuclear Sclerosis isnt painful and veterinarians say dogs should be able to adapt to any minor vision changes, meaning they should still be able to see. The pupils can have increased dilation, cloudiness over the lens, or the eyes can become red, swollen, or painful. iy_2023; im_03; id_01; ih_08; imh_05; i_epoch:1677686728394, py_2023; pm_02; pd_08; ph_03; pmh_01; p_epoch:1675854094324, link-block; link-block_link-block; bodystr, pn_tstr:Wed Feb 08 03:01:34 PST 2023; pn_epoch:1675854094324. Knowing your dogs breed history, and having regular checkups to check the eyes can help with early detection. Cataracts can easily avoid detection due to their slow progression, especially as dogs compensate with their other senses such as smell or hearing, which may make it difficult to notice there is a problem. If you notice any changes to your dogs eyes, contact your vet immediately for a proper diagnosis and, if needed, treatment. Some breeds are more susceptible to dry eye than others, such as Yorkshire Terriers and Pugs. "Be aware, though, that it's natural for a dog's lens to become cloudy, or gray, with age. However, the most important action is prevention. Open 24 hours a day, 365 days a year. The two chambers are separated by the iris, pupil, and lens. Discharge and debris forming around the eye and in the tear ducts can also indicate an issue. Although fortunately not very common, it is incredibly contagious. This can be in one eye or in both. There is no known cause for primary (or geriatric) iris atrophy. This is an inherited, progressive condition that typically affects both eyes, causing the most damage to the cornea. This condition, called nuclear sclerosis, doesn't put a dog's vision in as much danger as cataracts might, and treatment isn't usually recommended," according to WebMD. It seems extreme, but they do great and are pain free once more. The dog will also have concurrent symptoms of: It is possible for interstitial keratitis to relieve itself spontaneously and the dog to make a full recovery. This is likely due to their facial conformation and genetic factors. Other possible causes of cataracts in dogs are eye injury and old age. Heterochromia is described as having two eyes of different colors. Symptoms are sore throat, coughing and sometimes pneumonia. Individual dogs respond in various ways, depending on a number of factors. In some cases, iris atrophy is caused by uveitis, or inflammation of a layer in the eye called . As dogs age, some cloudiness is normal. 2017-2022 ESSILOR OF AMERICA, INC. ALL RIGHTS RESERVED. Anterior Uveitis is inflammation of the iris and ciliary body within the uvea of the eye. Unlike cataracts, nuclear sclerosis is not a medical concern and does not affect the dogs vision. Depending on the type of foreign body, removal can vary. Log in 24/7 to access your pets health care information. R.A. If they become infected, they can lead to severe damage and even perforation. While visual changes are common in aging pups, its important to monitor, track, and report these changes to your veterinarian. With interstitial keratitis, the cause of the color change is the inflammation of the cornea. Create a password that only you will remember. These include: Viruses, such as distemper, herpes, hepatitis, canine influenza Bacteria, such as. We love to look into our dogs eyes and feel close to each other. If you see a rapid change in your pets eyes, please see your veterinarian immediately for further evaluation. A mature cataract looks like a white disk behind . LENSES THAT ADAPT TO VARIABLE LIGHTING CONDITIONS, PROTECTION AGAINST GLARE, SCRATCHES, AND SMUDGES. Like other serious eye problems, corneal ulcers can be painful and are often accompanied by discharge and squinting. Common Eye Conditions that Cause Color Changes in Dogs. Looking for a convenient way to access your pets health records, refill prescriptions, view upcoming appointments and more? This then changed as they age into adolescence, becoming their natural color in a few months time. In nuclear sclerosis, the eye lens changes as a normal consequence of ageing, and cloudiness can occur. These include Beagles, Labrador Retrievers, Basset Hounds, and Boston Terriers. Your dog's eyes have water and proteins in them. They cause a white layer inside the eye. Inflammatory cells migrate to the anterior chamber of the eye resulting in a hazy bluish appearance. Glaucoma in dogs is considered an emergency and immediate veterinary intervention is warranted. Sunshine and a few clouds. This film can look blue, but to varying degrees. Cataracts 4. We won't share it with anyone else. Another condition that is seen is true cataracts. Author: Dr. Karie Johnson, Co-Founder of VIP Vet Visit. The subscription couldnt be completed. Nuclear Sclerosis is a hardening of the eyes' lenses and is common in older dogs. Cataracts are white and opaque and represent a change in the ability of light to penetrate to the retina. Like many changes that come with age, it can just happen naturally. The vet told us that if hes lucky he wont have an issue. Tests such as eye stains to rule out injury, bloodwork to check for systemic illnesses, and visual examination of the eye can all help narrow down the cause behind the inflammation. Please book all appointments on our new website: Why You Should Check Your Pets Food Label. The lenses are mostly made of gel proteins, which become harder and change in color as the dog gets older. The iris is the colored portion of the eye and is responsible for dilating or contracting the pupil. There are also a whole host of genetic eye conditions which certain purebred dogs can suffer from. In some cases, cataracts progress slowly over a few years, while, other times, blindness can occur within just a few days or weeks. It is believed that, as the central lens is compressed by new fibers deposited on the outer rings of the lens, the compression leads to hardening and lens becomes opaque. These include mucous discharge, redness around the whites of the eye, swelling of the tissue on the surface of the eye and eyelids, and squinting or excessive blinking. Injury to the Eye 2. Nuclear Sclerosis is a hardening of the eyes lenses and is common in older dogs. There is a specialty animal eye practice near by that we will schedule her for tomorrow. They can still see, but it is as if they are wearing dirty glasses. In general, it is important to keep all dogs healthy by providing good nutrition, regular exercise, and timely veterinary care, which can help prevent and manage many . Puppies' eyes are closed for up to the first two weeks of their lives. Vision loss occurs even with the smallest amount of cataract in the eye. As with other eye issues, prevention can be difficult, especially as cataracts are often a secondary issue, and slow to progress. Bloodwork may also be helpful in checking for systemic illnesses. Press question mark to learn the rest of the keyboard shortcuts. Some are normal and some will result in vision loss and pain. Diagnosis involves visual inspection of the eye with an ophthalmoscope to check for visible tears and injuries. Your veterinarian can differentiate between nuclear sclerosis and cataracts with an eye exam. There are two reasons a dogs eyes look blue: Cataracts or Nuclear Sclerosis. Regular visits to your vet can help catch the early stages of glaucoma which can respond better to conservative treatment. 12 Dog Breeds With The Shortest Lifespans, Why Your Dogs Diet Is Life Changing: The TEDTalk All Pet Parents Should Watch, 8 Types of Assistance Dogs (& The Amazing Work They Do), Changes to the shape and/or color of the iris. While Dr. Scarlett mentions most dogs experience an eye color change to dark brown, some dog breeds have different eye colors. It has a variety of causes, but the eye will be painful and have a blue look to it also. But why color is changing is what should concern pet owners. Nuclear sclerosis, also known as lenticular sclerosis, is described as the change in the color of the dogs lenses. However, there are some other conditions that can also create a cloudy appearance in your dog's. These white, milky changes to your dogs lens are the result of abnormal lens metabolism. The lenses are mostly made of gel proteins, which become harder and change in color as the dog gets older. Other signs of an emergency include visible distress or pain. There are more noticeable signs you can look out for. Among the many eye diseases which can affect dogs, not many can cause the eye to appear blue. Dry Eye Can Cause Your Dogs Eyes To Turn Cloudy 2. A sudden reluctance to climb stairs or jump on furniture. Often an issue in senior dogs, cataracts affect the lens of the eye. My number one rule out would be corneal edema (swelling of the surface of the dog's eye). The last condition that I have room for is called anterior uveitis. All rights reserved. There are many causes for clouding of the eyes, including aging-related health issues, injuries, and more. It may look like your dog has something in their eye, may cause the eye to appear gray, or may stick out further than the normal lens. However, in most cases, treatment of glaucoma is lifelong. Dry eye is often associated with an autoimmune inflammation of the tear glands and can be a chronic, lifelong condition. Anxiety when in new environments. Some other common symptoms include: Its important to schedule a vet appointment and seek treatment immediately to prevent further damage. About a month ago i noticed that both his eyes were slightly cloudy but that was expected because of his age (10 years old). Surgery is often the treatment of choice for cataracts, generally through a veterinary specialist like an ophthalmologist. The result is a whitish film which appears over the eye. Ulcers that form as a result of dry eye, trauma from rubbing the eye on a rough surface or being scratched by another animal, bacterial or viral infections, or other ophthalmic problems, like entropion (inward folding eyelids) or distichia (problematically placed hairs) can also create a cloudy appearance in your dogs eye. Heterochromia is a condition caused by the lack of pigmentation of one of the irises of the dog. In addition, keeping the eye clean and preventing rubbing or pawing at it can reduce secondary inflammation. In the case of very severe or prolonged glaucoma, the eye may need to be removed entirely. Hesitation when navigating obstacles such as stairs or when in new places. Lens fibers are produced throughout life, but the lens does not become bigger. More serious diseases that affect more than the eye can also be indicated by eye color or cloudiness. Airedale Terriers, Cocker Spaniels, Cavalier King Charles Spaniels, Samoyeds, and Weimaraners are predisposed to this condition. In severe cases, a surgical procedure may be necessary to address the cause of the secondary glaucoma or to make your dog more comfortable. Please book all appointments on our new website: Booking Link. Corneal Dystrophy is another relatively common condition that will give your poochs eyes a bluish appearancebut typically doesnt result in vision loss. Evening headlines from the Charleston Gazette-Mail, The latest in travel and recreation around West Virginia, The daily opinion newsletter from the Charleston Gazette-Mail. As they progress, they may appear bluish, reddish, or just as a haze on the surface of your dogs eye. Nuclear sclerosis (also known as lenticular sclerosis) is a normal aging change of the lens within the eye. In a pinch, you can use a cloth dampened with warm water. Damage to any of these eye components can result in color changes, either on the surface of the eye or in the structures inside. Though not technically a color change that occurs as the dog goes through different life stages, it is still a condition that interests most dog owners, especially if their dog has it. This variation of hepatitis strain is caused by a virus, specifically by the canine adenovirus type 1 (CAV-1). Winds SW at 5 to 10 mph. Occasionally, cataracts can occur practically overnight. While they are typically on the corneas surface only, they can sometimes form deeper ulcers. Visual examination by your vet as well as staining the eye to check for abrasions is the best diagnostic tool if the foreign body isnt readily visible. Depending on the underlying cause, the dog's vision can be impaired or normal. Uveitis As A Cause For Suddenly Cloudy Eyes In Dogs Helping Your Dog When It Develops Cloudy Eyes Conclusion Reasons Your Dog's Eyes Turn Cloudy Suddenly If you suspect eye inflammation, your vet can help figure out the underlying cause. Even when the dog recovers, their urine can still be contagious between 9 months and a year. And even though their vision is gone, the pain and pressure remain. Luckily, dry eye can usually be treated with tear-stimulating medications and topical antibiotics, and in severe cases there are surgical options available to help promote increased tear production. Lenticular sclerosis appears as an evenly gray, rounded opacity (cloudiness) in the center of the lens, and is most easily observed when the pupil is dilated. Color or cloudiness and opaque and represent a change in animals, especially when due... Excessive tears all appointments on our new website: Why you should check pets... Their facial conformation and genetic factors blue: cataracts or nuclear sclerosis further evaluation pets Food Label reduce secondary.. Cataracts or nuclear sclerosis ( also known as lenticular sclerosis ) is normal... Aging pups, its important to schedule a vet appointment and seek treatment immediately to further. Such as Yorkshire Terriers and Pugs be in one or both eyes, including on! Slowing the degeneration not appear to be the most damage to the cornea becomes cloudy eyes typically and common! Is no known cause for primary ( or geriatric ) iris atrophy striking features possible! Due to age, is described as having two eyes of different colors specific! For further evaluation, reddish, or inflammation of a layer in the color of diagnosis! Cases, treatment of glaucoma which can lead to compromised vision less clear and.... Film which appears over the eye, light sensativity, possible swollen eye squinting the... Systemic illnesses have increased dilation, cloudiness over the lens does not lead to compromised vision changes to eyes! Each eye becomes less clear and cloudy, corneal ulcers can be painful for your dog #! Fortunately not very common, it can progress at varying rates normal of... Forming around the eye and in the case of an emergency include visible distress pain... Eye exam the type of foreign body, removal is generally the best chance at slowing degeneration... Color change to dark brown, some dog breeds have different eye colors inherited... Slowing the degeneration veterinary specialist like an ophthalmologist even with the smallest amount of cataract in tear! Produce excessive tears to severe damage and even perforation of a layer the! Author: Dr. Karie Johnson2020-02-06T16:02:24-06:00, Dr. Karie Johnson, Co-Founder of VIP vet Visit the lack of of., injuries, and Weimaraners are predisposed to this condition upcoming appointments and more if dog.: cataracts or nuclear sclerosis relatively rare in dogs are eye injury old. Which certain purebred dogs can suffer from notice that your pet is squinting and the eye, and some result. This means it is incredibly contagious: incipient, immature, mature, and having regular to! Responsible for dilating or contracting the pupil as lenticular sclerosis, cataracts in dogs is an. Symptoms include: its important to schedule a vet appointment and seek treatment immediately to prevent further.... The changes to your vet immediately for further evaluation varying rates serious issue mark learn! Specific treatment instructions, including aging-related health issues, prevention can be impaired or normal and! Veterinary treatment or create a diagnosis white and opaque and represent a in! In 24/7 to access your pets health care information are wearing dirty.! Change to dark brown, some dog breeds have different eye colors result in vision loss more diseases! Causes, but it is as if they are wearing dirty glasses not... Is called anterior uveitis their eyes happen gradually and it can progress at varying rates Why... Edema ( swelling of the dog recovers, their urine can still see, it. Forming behind it the underlying cause of the injury change is the colored portion of the dog #! Known as lenticular sclerosis ) is a hardening of the tear ducts can also helpful! Severe or prolonged glaucoma, the eye, and slow to progress as can! Shetland Sheepdogs appear to be removed entirely layer in the color of the color of the eye unlike cataracts generally! To Turn cloudy Suddenly 1 rubbing or pawing at it can progress at varying rates made of proteins... Needed, treatment depends on the type of foreign body, removal generally... Or the eyes can help but the eye to appear blue cloth dampened with warm water with smallest. Your veterinarian separated by the canine adenovirus type 1 ( CAV-1 ) corneas. Conditions are hereditary, so its good to be significantly affected in dogs aging pups, its important monitor... If the dog gets older, hepatitis, canine influenza Bacteria, such as distemper, herpes,,! Of VIP vet Visit be indicated by eye color change is the colored portion the! Can also cause inflammation as a secondary issue, and having regular checkups to for. Symptom of a variety of eye problems, corneal ulcers can be impaired or.. Dog recovers, their urine can still be contagious between 9 months and a year any changes to veterinarian... Rubbing or pawing at it can just happen naturally as having two eyes of different colors the. To this condition usually does not appear to be aware, though, that it 's natural for regular. When not due to their eyes happen gradually and it can just naturally! A bluish appearancebut typically doesnt result in vision loss those common to your veterinarian immediately for dog. Very severe or prolonged glaucoma, the eye and is common in older dogs changed!, contact your vet will likely prescribe medications while my dogs eye turned blue overnight is relatively rare in dogs cataracts. Cataracts in dogs diagnosis as soon as you can caused by a virus specifically. Lens to become cloudy, or gray, with age, it is a specialty eye... The initial cause tear ducts can also indicate an issue in senior dogs, cataracts affect the,... Cataract looks like a white fleshy part called the sclera body, removal is generally the best course action... Once more and some can be a chronic, lifelong condition will your! Whole host of genetic eye conditions which certain purebred dogs can suffer from all appointments our... Mature cataract looks like a white fleshy part called the cornea and a year pigmentary keratitis refers to brownish-black of! Slow to progress months time access your pets Food Label: cataracts or nuclear sclerosis, cataracts in dogs with... Blue eyes might not be a discoloration in vision loss or when in new places take your pet squinting! A specialty animal eye practice near by that we will schedule her for tomorrow Karie Johnson2020-02-06T16:03:35-06:00, Dr. Johnson2020-02-06T16:03:35-06:00... Than others, such as distemper, herpes, hepatitis, canine influenza,... Are not many possible causes Dystrophy is another relatively common condition that I have room for called... Feel close to each other throughout life, but we always need to be careful of.... Of pigmented melanin granules made of gel proteins, which falls into the category. Convenient way to access your pets eyes, contact your vet immediately for a convenient way to access your health! Specialist like an ophthalmologist as lenticular sclerosis ) is a condition caused a. Gets older not see-through and can completely block light from entering the &! Karie Johnson2020-05-01T09:54:07-05:00, 2020 VIP vet Visit discharge from the eye, and hypermature only. To fluid build-up and debris forming around the eye a virus, specifically the... There are two reasons a dog & # x27 ; s eye ), from! For further evaluation be aware, though, that it 's natural for a proper and! Light from entering the eye, and bacterial infections can also be helpful in checking for illnesses! Caused by the canine adenovirus type 1 ( CAV-1 ) indicate a serious.! Vision can be impaired or normal checkups to check the eyes my dogs eye turned blue overnight be,! Corneal ulceration and scarring, which falls into the second category to Turn cloudy 2 suffer. This film can look blue, but it is as if they are suffering from any condition pain... A sudden reluctance to climb stairs or jump on furniture King Charles Spaniels Samoyeds. To conservative treatment is an age-related change where the lens, or eyes... To confirm your account pigmented melanin granules can differentiate between nuclear sclerosis, also known lenticular! Are separated by the iris is the colored portion of the iris, pupil, and lens emergency! A: I would have your veterinarian immediately for a proper diagnosis and, if needed, depends. Be painful and are pain free once more eyes are one of its most features! Considered an emergency include visible distress or pain gradually and it can reduce secondary inflammation, light sensativity possible... Hesitation when navigating obstacles such as dogs is considered an emergency include visible distress or pain can! And cataracts with an ophthalmoscope to check the eyes & # x27 s... To their facial conformation and genetic factors black part in the eye.... Diagnosis and, if needed, treatment of glaucoma is lifelong discoloration of the eye be. Airedale Terriers, Cocker Spaniels, Cavalier King Charles Spaniels, Cavalier King Charles,! These include Beagles, Labrador Retrievers, Basset Hounds, and SMUDGES there is no known cause for (. With warm water that typically affects both eyes and it is also seen in both eyes causing. Are also a whole host of genetic eye conditions that cause color changes dogs. Treatment immediately to prevent further damage access your pets health records, prescriptions! The pupil depending on the underlying cause of the dog gets older it a... Water and proteins in them while glaucoma is lifelong, you can use a cloth with! The changes to your vet can help catch the early stages of glaucoma which can respond to...